Patient Information Leaflets (PILs)

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These Patient Information Leaflets (PILs) are specially written by the British Association of Dermatologists (BAD).

The BAD has been awarded The Information Standard certification for the process it employs to develop information products aimed at the general public, which include PILs, Sun Awareness Campaign materials, and other information products.

The BAD shall hold responsibility for the accuracy of the information published, and neither the scheme operator nor the scheme owner shall have any responsibility for costs, losses, or direct or indirect damages or costs arising from inaccuracy of information or omissions in information published on the website on behalf of the BAD.

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5-FU cream is a treatment that selectively destroys sun-damaged cells in the skin whilst retaining the normal healthy skin cells. It has been in use for more than 50 years.

5-FU cream will induce inflammation in the skin. This will consist of redness, soreness, oozing, crusts and scabs. After completing the treatment course this reaction will settle over a few weeks. Sometimes your doctor may recommend using a steroid cream to help settle the inflammation more quickly.

In the UK, two forms are available: 5% 5-FU cream (Efudix®) and 0.5% 5-FU combined with 10% Salicylic acid (Actikerall®).

Acitretin (trade name Neotigason) is a member of a group of drugs called retinoids, closely related to Vitamin A. It works by slowing down cell reproduction in the skin.

Acne is a very common skin condition characterised by comedones (blackheads and whiteheads) and pus-filled spots (pustules). It usually starts at puberty and varies in severity from a few spots on the face, neck, back and chest, which most adolescents will have at some time, to a more significant problem that may cause scarring and impact on self-confidence. For the majority it tends to resolve by the late teens or early twenties, but it can persist for longer in some people.

Acne can develop for the first time in people in their late twenties or even the thirties. It occasionally occurs in young children as blackheads and/or pustules on the cheeks or nose.

Actinic keratoses are areas of sun-damaged skin found predominantly on sun-exposed parts of the body, particularly the forearms, backs of the hands, face, ears, bald scalp and the lower legs. They may also occur on the lips. The terms actinic and solar are from Greek and Latin, respectively, for ‘sunlight-induced’, and the term keratosis refers to thickened skin. Actinic keratoses may be unsightly, sometimes they can itch, but generally are harmless. There is a very small risk that the patches could progress into a form of skin cancer called squamous cell carcinoma. Nonetheless, patients who have actinic keratoses are more at risk of all types of skin cancer compared to someone of the same age without actinic keratoses. Patients most at risk are those who have numerous actinic keratosis patches and those on immunosuppressive drugs for accompanying conditions.  Actinic keratoses are not contagious.

The term 'actinic prurigo’ is the term used for a rare (less than 1:1,000) type of skin sensitivity induced by sunlight (photosensitivity); 'actinic' is Greek for 'sunlight', ‘pruritus’ is the medical term for itching, and ‘prurigo’ is a related word which describes the changes that appear in the skin after it has itched and been scratched for a long time. In actinic prurigo the skin becomes firm, raised and itchy on the areas of the skin surface which are exposed to the sun.

Adalimumab is a powerful drug that has been specially designed to mimic normal human molecules, and for this reason it is classed as a ‘biological’ drug. It reduces inflammation by inhibiting the activity of a chemical ‘cytokine’ in the body called ‘tumour necrosis factor alpha’ (TNF-alpha). 

Alitretinoin (trade name Toctino) is a drug belonging to a group of medications called retinoids. Alitretinoin is a form of vitamin A and works by reducing skin cell turnover. It also helps to reduce skin inflammation.

Alopecia is a general term for hair loss. Alopecia areata is a common cause of non-scarring (does not cause scarring to the scalp) hair loss that can occur at any age. It usually causes small, coin-sized, round patches of baldness on the scalp, although hair elsewhere such as the beard, eyebrows, eyelashes, body and limbs can be affected. In some people larger areas are affected and occasionally it can involve the whole scalp (alopecia totalis) or even the entire body and scalp (alopecia universalis).

It is not possible to predict how much hair will be lost. Regrowth of hair in typical alopecia areata is usual over a period of months or sometimes years, but cannot be guaranteed. The chances of the hair regrowing are better if less hair is lost at the beginning. Most people, with only a few small patches get full regrowth within a year. If more than half the hair is lost then the chances of a full recovery are not good. The hair sometimes regrows white, at least in the first instance. Most people get further attacks of alopecia areata. In alopecia totalis and alopecia universalis, the likelihood of total regrowth is less. 

Atopic eczema is an extremely common inflammatory condition of the skin. It may start any age but is most common in children, affecting 1 in every 5 children in the UK at some stage. The term ‘atopic’ is used to describe a group of conditions which include asthma, eczema and hay-fever. These conditions are linked by an increased activity of the allergy component of the immune system.

An atypical fibroxanthoma (AFX) is an uncommon (< 0.2 % of all skin cancers) type of skin cancer that occurs mainly in older people after the skin of the head and neck has been damaged by sunlight and/or by radiotherapy used to treat a previous cancer.

Atypical mole syndrome is a disorder of the skin which is seen in approximately 2% of the population. It is defined when an individual has more than 50 moles composed of melanocytes (pigment producing skin cells) present on their skin, and three or more are atypical (unusual) in their appearance, e.g. size and shape. An atypical mole is one greater than 5 mm in diameter, often with flat and raised areas, often oval rather than round, and often with some colour variation.

Solitary atypical moles are individually benign moles with a low risk of progression to melanoma (a type of skin cancer). However, people with multiple atypical moles (atypical mole syndrome) are considered to have a higher risk (increased 7 to 10 fold) of developing melanoma compared to the general population, due to the presence of atypical molesespecially if some of these moles are on the scalp, buttocks, or feet.The risk is increased further if one or more first or second degree relatives (i.e. a close blood relative including parents, full siblings or children, or a blood relative including grandparents, grandchildren, aunts, uncles, nephews, nieces or half-siblings, respectively) have been diagnosed with malignant melanoma; this combination is known as familial atypical mole syndrome.

Azathioprine has been available since the 1960s. It was developed initially to stop rejection of transplanted organs, such as kidneys. It is now used to treat a wide range of illnesses. It works by suppressing the body’s own defence system (the immune system), either by itself or in combination with other drugs. Azathioprine is not a steroid and is considered to be safer in the long-term than steroid tablets.

A basal cell carcinoma (BCC) is a type of skin cancer. There are two main types of skin cancer: melanoma and non-melanoma skin cancer. BCC is a non-melanoma skin cancer, and is the most common type (greater than 80%) of all skin cancer in the UK. BCCs are sometimes referred to as ‘rodent ulcers’. 

‘Naevus’ is Latin for birthmark. Dr Samuel Becker, an American dermatologist, described two men with a brown patch of skin with hair-growth on the upper body in 1949. Becker’s naevus is sometimes called ‘Becker's melanosis’ or ‘pigmented hairy epidermal naevus’.

Blue rubber bleb naevus syndrome has also been called ‘Bean syndrome’ after Dr William Bean, who described it. It is caused by the congenital development of multiple venous malformations in the skin, soft tissues and gastrointestinal tract (intestine).

A ‘syndrome’ is a group of signs and symptoms that occur together. ‘Naevus’ is Latin for ‘birthmark’. The ‘blue rubber blebs’ are small areas of blue mis-shaped veins with a rubber-like feel.

In some people, blebs are only seen in the skin. They can also occur in any other part of the body, most commonly the intestine. 

A boil, or furuncle, is an abscess (infection) of the skin that starts in the deep part of the hair follicle.  The infection is usually caused by a bacterium called Staphylococcus aureus (S. aureus)Occasionally the infection may spread into the surrounding tissues (cellulitis) and can cause fever and a feeling of being unwell.  When several boils form close together and join beneath the skin, it is known as a carbuncle.  Sometimes rarer strains of S. aureus: Methicillin resistant Staphylococcus aureus (MRSA) and Panton-Valentine leukocidin (PVL), can give rise to boils.  The latter may cause boils which are larger and more painful (see Patient Information Leaflet on PVL Staphylococcus Aureus (PVL-SA) skin infection).

The bacteria causing the boil can occasionally spread from one part of the body to another and from one person to another by skin-to-skin contact and contaminated clothing and towels.  This is especially true when boils are caused by the PVL strain of S. aureus bacteria.  Boils are common in adolescents and can affect boys more often than girls. Sufferers of boils seldom have a problem with their immune system, but boils can be more severe in patients with a suppressed immune system.  Boils are more common in patients with diabetes and those who are overweight.  

Squamous cell carcinoma in situ, often called Bowen’s disease, is a growth of cancerous cells that is confined to the outer layer of the skin. It is not a serious condition, and its importance rests on the fact that, very occasionally, it can progress into an invasive skin cancer known as squamous cell carcinoma (see Patient Information Leaflet on Squamous Cell Carcinoma for further information). For this reason, dermatologists usually treat, or at least monitor, Bowen's disease.

There are two types of topical calcineurin inhibitors called tacrolimus ointment (Protopic 0.03% and 0.1%) and pimecrolimus cream (Elidel). They are classified as immunomodulating agents.  This means that they act on the immune system to reduce skin inflammation. Both tacrolimus and pimecrolimus block a chemical called calcineurin which activates inflammation in the skin and causes redness and itching of the skin. 

The “vulva” is the term used to describe the visible part of the female genitalia. The skin of the vulva is sensitive and can be easily irritated by everyday products including soap, bubble baths, shower gels, talcum powder, cleansing wipes, perfumes, deodorants, antiseptics, fragranced washing powders and fabric conditioners. Such products may make your skin sore and uncomfortable.

Erysipelas and cellulitis are infections of the skin. Erysipelas is a superficial infection, affecting the upper layers of the skin, while cellulitis affects the deeper tissues. They can overlap, so it is not always possible to make a definite diagnosis between the two.  

Chondrodermatitis nodularis is inflammation of the skin of the ear. This Latin/Greek name literally means an inflammation both of the cartilage (chondro-) and of the skin (-dermatitis) causing a bump (a nodule, hence nodularis).

It is common and harmless, but can be tender when touched. 

The term ‘chronic actinic dermatitis’ or “CAD” is used to describe a particularly severe form of eczema in which sensitivity to light is the main feature (photosensitivity). CAD is chronic, that is to say it typically persists for a number of years. ‘Actinic’ means “caused by sun” and ‘dermatitis’ (which is another term for eczema) means itchy inflammation of the skin. 

Paronychia is a common infection of the skin around the finger or toenails (the nail folds). There are two types - ‘acute paronychia’ develops quickly and lasts for a short period of time; and ‘chronic paronychia’ develops slowly, lasting for several weeks and often comes back. Chronic paronychia is not caught from someone else. 

Like penicillin, ciclosporin was discovered as a substance produced by a fungus. Ciclosporin was found to suppress the immune system and was initially developed for suppressing the immune system of transplant patients to prevent them rejecting their transplanted organs. It was subsequently found to benefit patients with a range of diseases caused by immune reactions.

Colchicine is an extract of the plant Colchicum autumnale (autumn crocus), used medically since ancient times.

Colchicine modifies the response of the immune system. It has been found to be helpful in conditions with too many neutrophils (a type of white blood cells) in the skin.

Congenital erythropoietic porphyria (CEP), also called Günther’s disease after the doctor who first described it, is the rarest of the porphyrias. It is estimated that about 1 in every 2-3 million people are affected by CEP, which affects males and females equally, and occurs in all skin types.

The word ‘congenital’ means a condition that exists at birth and often before birth, or that develops during the first month of life; ‘erythropoietic’ means associated with red blood cells and their formation.

Dermatitis describes a specific type of inflammation of the skin. Dermatitis and eczema are two terms used to describe the same pattern of inflammation. Contact dermatitis describes inflammation which is caused by contact with something in the environment. It may sometimes be referred to as contact eczema.

The term ‘cryotherapy’ literally means ‘treatment using low temperature’, and refers to the removal of some skin lesions by freezing them. The most common product used by doctors is liquid nitrogen. 

Amyloidosis describes a group of rare conditions in which abnormal proteins, known as amyloid, accumulate in various organs. Amyloid (Latin ‘amylum’ means starch) has a characteristic, ‘starch-like’ appearance under the microscope.

In the forms of cutaneous amyloidosis discussed in this leaflet, only the skin is affected, but usually no other organs. Only very seldom does the rarest of the three main types of cutaneous amyloidosis, nodular localised cutaneous amyloidosis, develop into systemic amyloidosis with internal organ involvement. On the other hand, patients with multiple myeloma, which is a form of cancer of cells in the blood and bone-marrow, can also develop nodular localised cutaneous amyloidosis.

Cutaneous amyloidosis is rare in Western populations and occurs more commonly in South-East Asia, South America and some populations of the Middle East. It starts early in adult life and then tends to persist.

Cutaneous amyloidosis can occur together with or as a result of other chronic skin conditions, most commonly atopic eczema.

Vasculitis is a term referring to inflammation of blood vessels. These vessels may be arteries, veins or both, and vasculitis can affect any part of the body. When it affects small or medium sized blood vessels in the skin, it is known as cutaneous vasculitis. Occasionally cutaneous vasculitis can be a sign of inflammation occurring in other organs (a systemic vasculitis) and further investigation may be required for a full diagnosis.

By definition, cysts are closed sacs that have two main features:

  • A lining
  • Contents that are liquid or semi-solid

The lining. Differences between the lining of epidermoid and pilar cysts can be seen under the microscope:

  • The lining of an epidermoid cyst looks like the epidermis (the outermost layer of cells in the skin)
  • The lining of a pilar cyst is made up of cells like those found in the roots of hairs

The contents. Both types of cyst contain a cheesy material, looking rather like toothpaste. This is made of soggy keratin - the material that makes up hair and the outer layer of the skin.

Dapsone is an antibacterial medicine belonging to the sulphonamide class of antibiotics. It is available only on prescription. It acts as an anti-inflammatory drug and has been used successfully as a treatment for several skin conditions such as dermatitis herpetiformis, pyoderma gangrenosum, Sweet’s syndrome and vasculitis for many years. Sometimes it can be used for other inflammatory skin conditions that are not mentioned here if none of the usual treatments are effective.

It is a rare inherited skin condition characterised by the loss of binding (acantholysis) between skin surface cells and there is also some thickening of the skin. It is also known as Keratosis Follicularis. The nails and mouth may also be affected. 

Dermatitis herpetiformis is a rare, very itchy and persistent blistering skin eruption, affecting between 0.4 and 3.5 people per 100,000 of the European population. It typically affects Caucasians aged between 15-40 years and is more common in men, but can occur in all age and racial groups.

A dermatofibroma is a common overgrowth of the fibrous tissue situated in the dermis (the deeper of the two main layers of the skin). It is quite harmless and will not turn into a cancer. Another name for dermatofibroma is histiocytoma.

Dermatofibrosarcoma protuberans (DFSP) is a very rare type of skin cancer. It usually occurs on the trunk, often the chest and shoulders; however it can also affect the limbs, head and neck. It starts in the deep layer of the skin (the dermis) and can invade deeper tissue such as fat and muscle. Although it grows very slowly, it can become quite large. As the edges are indistinct DFSP can come back even if apparently completely removed by surgery. It can, however, be cured if completely removed with a wide margin of normal tissue, or with a specialised form of surgery called Mohs surgery. DFSP almost never spreads to other parts of the body.

Dermatomyositis is a rare condition that causes inflammation in both the skin and the muscles. The word comes from the Latin for skin (dermis), muscles (myos) and inflammation (-itis). Very rarely only the skin is affected and not the muscles.

A digital myxoid cyst (sometimes called a mucous cyst) is a benign swelling that occurs on the fingers or, sometimes, the toes. Digital myxoid cysts are not contagious and are not a form of skin cancer.

The term cyst is from the Greek kystis meaning a bag or pouch; myxoid and mucoid refer to the jelly-like contents. Digital derives from the Latin digitus, meaning finger or toe.

Digital myxoid cysts occur most frequently in people in their sixties.

Eczema (also called dermatitis) is a term used to describe conditions where there is inflammation affecting mainly the outer layer of the skin (the epidermis). There are several different types of eczema, and in some cases the cause is known whilst in others it is not.

Discoid eczema is one type of eczema with characteristic round or oval red patches of inflamed skin. Discoid eczema is sometimes also called “nummular” eczema - nummular meaning coin-shaped and discoid meaning disc-shaped.

Discoid eczema is more common in men than women.  Men tend to develop the skin condition over the age of 50, whilst women are more likely to develop it in their teens or twenties. It is rare in children; however, it can be seen in both sexes at any time of life.

Discoid lupus erythematosus is an uncommon rash, usually made worse by exposure to sunlight. The term ‘lupus erythematosus’ is applied to a range of related disorders. At one end of the range is ‘systemic’ lupus erythematosus, which can damage internal organs, whilst right at the other end of the range is ‘discoid’ lupus erythematosus, which is confined to the skin and does not cause general ill health.

Dissecting cellulitis of the scalp is a rare inflammatory scalp condition. Pus-filled spots and lumps develop with subsequent hair loss over the affected area. Hair loss is permanent due to the inflammation which destroys the hair follicles and leaves scar tissue.

The condition is occasionally referred to as perifolliculitis capitis abscedens et suffodiens. It usually affects darker-skinned adult men, especially those of Afro-Caribbean origin, but can affect any race, sex or age.

DSAP is a skin condition manifested by multiple, dry, scaly rings, each measuring up to 1 cm (1/2 inch) across. They are found mainly on the forearms and legs. It is due to excessive sun exposure causing thickening of the skin.  It is sometimes confused with actinic keratosis which is also caused by sun exposure (See Patient Information Leaflet on Actinic Keratoses); however, actinic keratosis is more likely to arise on the face and hands.

DSAP is twice as likely to develop in women compared with men and is more common in lighter skin type. Itnormally develops between 30-50 years of age. It is not contagious. 

Dystrophic epidermolysis bullosa (DEB) is a rare inherited skin disorder. The skin of those who have DEB is more fragile than normal. Minor injury causes blisters which often leave scars when they heal. DEB can be mild, causing little more than minor inconvenience, but it can also be severe, affecting the mouth, gullet and eyes in addition to the skin. DEB is not an infection, it is not contagious and it is not due to an allergy.

Dystrophic epidermolysis bullosa (DEB) is divided into two major types depending on inheritance pattern: recessive dystrophic epidermolysis bullosa (RDEB) and dominant dystrophic epidermolysis bullosa (DDEB). Each type is further subdivided into multiple clinical subtypes.

DEB is different from the other forms of epidermolysis bullosa (EB), which include epidermolysis bullosa simplex, junctional epidermolysis bullosa and Kindler Syndrome. Individuals who have DEB will not develop one of the other types of epidermolysis bullosa at a later date. 

Eccrine porocarcinoma is a rare type of skin cancer involving the sweat glands. Sweat glands are present in the skin, with the highest density on the palms, soles, face and scalp.

Eccrine porocarcinoma is typically a slow-growing tumour which is often seen in those who are over 60 and occurs equally in men and women. Eccrine porocarcinoma can, rarely, spread to internal organs in the body.

Eczema herpeticum is a widespread, potentially serious infection of the skin that can affect people with atopic eczema.

Epidermolysis bullosa (EB) simplex is a rare inherited disorder in which the skin is fragile and blisters at sites of rubbing. It is mild in the usual form; blisters tend to be confined to the palms and soles, and are most troublesome during warm weather. In other types the blistering may be more generalised and occasionally blisters arise in the mouth. The most severe form is called EB simplex Dowling-Meara and those affected have more widespread blistering which does not vary according to the time of year.

EB simplex is different from other types of EB which include junctional, dystrophic and Kindler forms; if you have EB simplex then you will not go on to develop these other types of EB. EB simplex is not an infection, it is not contagious and it is not due to an allergy.

Erythema multiforme (EM) is a hypersensitivity reaction which tends to develop abruptly. Usually it will disappear on its own, but sometimes treatment may be required for the symptoms. It occurs in all racial groups and is predominantly observed in young adults (20-40 years), but can occur in any age group. The condition is slightly more common in men. 

Erythema multiforme is characterised by the sudden development of few to hundreds of red papules (spots). The papules usually begin over the back of the feet and hands, and spread upwards towards the trunk. The face is often involved. The hands and arms are more commonly affected than the feet and legs. Over time these papules evolve to plaques (raised patches) and then typical target shaped lesions. These target lesions have a dusky red centre, a paler area around this, and then a dark red ring round the edge. Sometimes the centre of the target can be crusted or blistered. The targets can be different shapes and sizes, hence the latin name: erythema (redness) multi (many), forme (shapes). 

Erythema multiforme is usually mild - 'erythema multiforme minor' – with only skin involvement, causing little trouble and clearing quickly.  There is also a rare but more severe type, 'erythema multiforme major', which has similar skin features to EM minor, but additionally there is involvement of one or more mucosal membrane (e.g. the lips, the inside of the mouth, the windpipe, the gullet, the anus or genital area, and the eyes) and usually some associated symptoms, such as fever or joint pain.

Erythromelalgia (or erythermalgia) is a rare condition. It causes intermittent, painful swelling and redness of the feet or hands. Sometimes the legs and arms can be affected, or, less often, other areas such as the ears or nose. It usually affects both sides of the body. In ancient Greek, ‘Eythros’ means ‘red’ and ‘melalgia’ means pain in a limb.  Early-onset erythromelalgia starts before the age of 25, and late-onset develops between the ages of 40 to 60. 

The word ‘erythropoietic’ means associated with red blood cells (‘erythro-’) and their formation (‘-poietic’). The porphyrias are a group of uncommon diseases caused by something going wrong with the production of chemicals known as porphyrins. These chemicals are the building blocks of haem, which, when combined with a protein (globin), forms haemoglobin, the material in red blood cells that carries oxygen round the body. In the case of EPP and XLDPP, there is a build-up of one of these porphyrins (protoporphyrin) in the blood, especially in the red blood cells. This leads to asensitivity to sunlight. 

Etanercept is one of the first of a group of modern drugs called ‘biologics’ or ‘biologicals.’ Unlike ordinary drugs which can usually be made from chemicals in a test tube, biologics are complex molecules made by living cells. They are designed to mimic or change processes in the human body and are used to treat a range of diseases from cancer to arthritis.

Etanercept blocks the effect of tumor necrosis factor alpha (TNF-alpha) so it is called an ‘anti-TNF’ drug. TNF-alpha helps the body fight infection and cancer, but when over produced it can have harmful effects. Over-production of TNF occurs in several diseases including Crohn’s disease, psoriasis and inflammatory arthritis, so anti-TNF drugs have been as treatment.

Extra-mammary Paget’s disease (EMPD) is a rare, slow-growing disease that is usually due to a pre-invasive type of skin cancer. Usually it is confined to the skin, but in approximately 20% of the cases it can be associated with an invasive cancer more deeply. It typically looks similar to a patch of eczema. It usually affects skin in the genital area and around the anus of both males and females. It is commonest in people aged between 50-60 years. It can be primary, when its origin is in the skin, or secondary, when it comes from other adjacent regions internally like urethra, cervix, bladder or bowel. Paget’s disease, in contrast, refers to the same type of changes affecting the breast or nipple.There is no relation to another disease called Paget’s disease of the bone.

Hairs are formed within the skin in tiny structures known as hair follicles. The word folliculitis describes an inflammation of these hair follicles. This may happen anywhere on the skin; the term folliculitis barbae is confined to inflammation of the hair follicles in the beard area (‘barba’ is the Latin word for beard).

Folliculitis decalvans is a rare chronic (long term) inflammatory condition of the scalp. Very rarely it can affect other hair-bearing skin such as beard, armpits, pubic area and legs. The prolonged inflammation that usually occurs leads to scarring. Folliculitis decalvans is derived from Latin and means inflammation of the hair root associated with hair loss.

Folliculitis decalvans is not contagious and is not a type of skin cancer.

Fox-Fordyce disease is a disease of the apocrine sweat glands of the skin. These are special sweat glands found on the armpits, genital region and breasts that produce a more dense secretion than the normal eccrine sweat glands. Patients with this condition experience itchy bumps on the skin near to hairs.

Frontal fibrosing alopecia is a form of scarring hair loss affecting the hair margin on the front of the scalp. This happens due to inflammation and destruction of the hair follicles. There may also be hair loss around the ears and from the eyebrows. It most commonly occurs in women who have gone through menopause but can also occur in pre-menopausal women and, rarely, in men. It is thought to be a variant of another condition called lichen planopilaris

The fumaric acid esters (FAE) are a medicine used to treat psoriasis, and have been used to treat psoriasis for over 30 years. The FAE are a popular licensed oral treatment for psoriasis in some countries; however, they are not yet licensed for treating psoriasis in the UK. You may, however, be prescribed them by your dermatologist.

Fungal infections of the nails are also known as dermatophytic onychomycosis, or tinea unguium. The responsible fungus is usually the same as that that causes athlete’s foot – a common fungal infection of the skin of the feet, especially between the toes. In athlete’s foot the responsible fungus lives in the keratin that makes up the outer layer of the skin. When the fungus spreads to the keratin of the nails, the result is a fungal nail infection. 

Granuloma annulare is an uncommon skin condition, which most often affects children and young adults but can occur at any age. It is twice as common in women as in men. The reason for this is unknown. 

It usually presents as groups of small firm bumps in the skin which come together to form a characteristic ring shaped (annular) patch. These typically occur on only one or two sites of the body, often overlying bony areas such as the back of the hands, the feet, elbows or ankles. 

A ‘haemangioma’ (Greek for blood-vessel-growth) of Infancy is a benign overgrowth of blood vessel cells in the skin. The term ‘strawberry naevus’ or ‘strawberry haemangioma’ is used for a haemangioma that looks like a strawberry.

Hailey-Hailey disease is also known as familial benign chronic pemphigus. It is a rare inherited skin condition in which red scaly areas that can be itchy and sore can lead to superficial blisters and eroded (broken) areas of the skin folds of the groin, armpits, neck and under the breasts. The condition flares intermittently and tends to come and go. Many patients are able to lead full and normal lives, with their condition being a nuisance rather than a serious problem. Some patients are more severely affected and experience more persistent painful raw areas of the skin with development of superficial blisters.

Female pattern hair loss (FPHL) has also been called androgenetic alopecia. It is the most common type of alopecia (hair loss) in women and the severity can vary.

Male pattern hair loss (MPHL) is the most common type of hair loss in men. It is also known as androgenetic alopecia. It affects about 50% of men over the age of 50.

Hand dermatitis is also called hand eczema. It is common and can affect about one in every 20 people. It can start in childhood as part of an in-built tendency to eczema, but is commonest in working-age adults. Hand dermatitis may be a short-lived, mild problem. However, in some people it lasts for years in a severe form that can have a great impact on daily life and restrict someone’s ability to work.

Head lice are common. They are small (adult lice are 3 - 4 mm long) greyish parasitic insects that live only on human scalps. They cannot fly, or jump, or burrow into the scalp, but their six legs are perfectly adapted for clinging firmly onto scalp hairs. Their presence does not imply a lack of cleanliness.

Head lice are usually picked up from someone who has them by head-to-head contact; it takes about 30 seconds for a louse to transfer from one scalp to another.

Herpes simplex is an infection of the skin with the herpes simplex virus. There are two types of herpes virus, called herpes simplex type 1 and herpes simplex type 2. Herpes infection is caught from another person through contact with mouth, eye or genital secretions or through direct contact with an active lesion. Herpes simplex type 1 usually infects the mouth or eye and herpes simplex type 2 usually infects the genital area. After the virus infects the person, whether it shows on the skin or not, it goes to local sensory nerves and lies hidden (dormant) until reactivation (recurrence of the herpes infection). Reactivation can occur after a few weeks or even years, when the virus travels to the skin supplied by the nerve and appears as a blister or rash on the skin. The commonest areas to be affected by herpes simplex are the lips (as cold sores), and the genital area (as genital herpes). Genital herpes infection is usually a sexually transmitted disease.  

Hidradenitis suppurativa is a chronic, recurrent, and painful disease in which there is inflammation in areas of the apocrine sweat glands. These glands are found mainly in the armpits and groins. Within hidradenitis there is a blockage of the hair follicles. This causes a mixture of boil-like lumps, areas leaking pus, and scarring.

Hidradenitis tends to begin in early life, and is more common in women, black and Mediterranean people. It affects about 1% of the population.

Hirsutism refers to excessive growth of dark, thick and coarse hair in an individual (usually female) in a male pattern. Commonly affected areas are upper lips, chin, central chest, midline of the stomach, lower back, buttocks and front of thighs. Hirsutism affects approximately 10% of women in Western societies and is commoner in those of Mediterranean or Middle-Eastern descent.

If the excessive hair is generalised and not in a gender specific pattern, the term is ‘hypertrichosis’, which means increased (‘hyper’) hair (‘trichosis’). In this leaflet we will only discuss hirsutism.  

Our hands come into daily contact with many substances such as soap, detergent, shampoo, household cleaning chemicals, water and food. These can take away the protective oils that keep the skin moist, leading to chapping, dryness, and irritation.  Frequent contact with water is one of the commonest causes.  Once the skin on the hands is irritated and damaged, it is prone to further damage and a vicious circle is set up leading to hand dermatitis, or making existing dermatitis worse.     

You may have been diagnosed with a skin cancer that rarely can spread into the lymphatic system, for example melanoma or squamous cell carcinoma.

As part of your examination the lymph nodes are examined by your doctor at follow-up appointments. The lymph nodes examined depend on the location of your skin cancer, e.g. if the skin cancer was on your leg then the lymph nodes in your inguinal area (groin) will be felt, or, if the skin cancer was on your face then the nodes in the head and neck would be examined. The aim is to detect any enlargement of the lymph nodes and undertake investigation at an early stage.

Some people express a wish to check their own lymph nodes between clinic appointments. The aim is to ensure that, in the unlikely event that there is spread of your skin cancer to the lymph nodes, it is detected and reported to your doctor or nurse straight away, rather than waiting until your next clinic appointment.

Hydroa vacciniforme is an extremely rare skin condition in which there is an abnormal sensitivity of the skin to sunlight (photosensitivity). It is neither infectious nor dangerous, but it can restrict an affected person’s lifestyle, particularly during the summer months and on holidays.

The term hydroa is possibly from the Greek for ‘watery eggs’, a reference to the blisters that characterise this condition; vacciniforme derives from the Greek for the ‘pox-like’ permanent scars (resembling large deep chicken pox scars) that result when the blisters heal.

Hydroa vacciniforme usually affects children aged 3-15 years, and is more common in females than males. In boys, hydroa vacciniforme may develop at a later age than in girls, and go on for longer.

Hydroxycarbamide, formerly known as hydroxyurea, affects cells that are dividing rapidly, such as the skin cells in psoriatic plaques and the blood cells in the bone marrow. It is mainly used for cervical and blood cancers, but is also used to treat psoriasis. It is known as a ‘cytotoxic’ medicine, meaning that it interferes with cell growth. 

Hydroxychloroquine is one of several antimalarial drugs that have anti-inflammatory effects useful in other diseases. It is licensed in the UK for the treatment of malaria.

Hydroxychloroquine is particularly effective for systemic lupus erythematosus (SLE) and discoid lupus erythematosus (DLE). By reducing inflammation, hydroxychloroquine can decrease pain, swelling and stiffness of joints, and improve or clear some rashes.

Hyperhidrosis means excessive sweating. It can be localised or affect the whole body.

Sweating is controlled by the brain, which sends signals along nerves called “sympathetic nerves” to the small sweat glands in the skin. These nerves are part of the “autonomic nervous system” which controls many unconscious body functions.

Increased sweating is a normal response to a rise in body temperature, and to emotions such as anxiety.

A treatment which reduces sweating is called an antiperspirant. This is different from a deodorant, which reduces odour, usually through an antibacterial effect. The two are often combined in the same product.

Ichthyosis is the term used to describe continual and widespread scaling of the skin. It may be inherited (genetic) or acquired during life. The inherited forms are rare, generally present from infancy, and are usually lifelong conditions. Acquired ichthyosis can develop at any age due to a number of medical problems, such as kidney disease. 

The commoner forms of inherited ichthyosis are mild and do improve during warmer weather. There are a number of very rare conditions where ichthyosis occurs with problems in other systems of the body. Each of the major types of ichthyosis will be discussed briefly, followed by an outline of the management.

Imiquimod is a topical immuno-modulator. The cream triggers the immune system to recognise abnormal cells and causes inflammation to remove them. It may also remove abnormal cells from the lymph drainage vessels around a tumour.

In the UK, two strengths of Imiquimod cream are available, a 5% cream (trade name Aldara®) and a 3.75% cream (Zyclara®). 

This leaflet has been written to give you information aboutimmunisations (vaccinations), which may affect you when you are taking medicines that act by suppressing the immune system. This includes information about vaccinations which are:

1.    Recommended before you start immune suppressing medicines

2.    Safe for you to have while you are taking this treatment

3.    Need to be avoided 

Impetigo is a bacterial infection of the surface of the skin. In the UK it is the most common skin infection seen in young children.

Infliximab is a powerful anti-inflammatory drug that has been designed to resemble normal human molecules, and is therefore classed as a “biological” treatment. It reduces inflammation by inhibiting the activity of a chemical (“cytokine”) in the body called ‘tumour necrosis factor alpha’ (TNF-alpha).

This is a procedure involving the injection of a steroid solution into abnormal skin, with the aim of improving its appearance or reducing symptoms such as itch or pain. The steroid preparation most frequently used in this procedure is called triamcinolone acetonide, and you may hear the procedure referred to as “intralesional triamcinolone”. 

Iontophoresis (pronounced eye-on-toe-for-ee-sis) is a safe and effective treatment that can be used to reduce excessive sweating (hyperhidrosis) of the hands, feet and underarms.

Isotretinoin is a member of a group of drugs, closely related to vitamin A, called retinoids. Isotretinoin is the generic name of a drug marketed by a number of companies, but the original brand name was Roaccutane. It works in a variety of ways, targeting several of the factors that cause acne and other skin conditions including the production of sebum (an oily substance produced by the skin) and the production of keratin (outer scales of skin) that block the pores of the hair follicle and cause acne.

Junctional epidermolysis bullosa (JEB) is a rare inherited (genetic) skin disorder. It is different from the other forms of epidermolysis bullosa (EB), which include epidermolysis bullosa simplex, dystrophic epidermolysis bullosa and Kindler Syndrome. Individuals who have JEB will not develop one of the other types of epidermolysis bullosa at a later date.

The skin of those who have JEB is fragile and minor everyday knocks and friction cause blisters or raw areas. There are 3 main types of JEB (Herlitz JEB, Non-Herlitz JEB and JEB with pyloric atresia). JEB varies in severity, from relatively mild disease with normal lifespan to the most severe form, Herlitz JEB, in which babies may not live beyond their first birthday. JEB is not an infection, it is not contagious and it is not due to an allergy.

JXG is a skin lump caused by an excess of cells known as histiocytes. It is rare and occurs mainly in infants and young children, although about 10% occur in adults. It is not known what causes this condition. It is not a type of cancer.

Kaposi’s sarcoma (KS) is a growth of the cells from the inner lining of blood vessels. It is linked to infection with Human Herpes virus type 8 (Kaposi sarcoma herpes virus, HHV8), and impairment of the immune system. It is named after Dr Moritz Kaposi, a Hungarian dermatologist, who first described it in 1872. ‘Sarcoma’ (from ancient Greek ‘flesh’) means a cancerous growth of the soft tissues under the skin and is present in other organs. Kaposi’s sarcoma is actually not a cancer, but rather a tissue-overgrowth.

Kaposi’s sarcoma can be mild, only affecting the skin, or more extensive with involvement of lymph nodes and internal organs such as the lungs or digestive system, in which case it may be fatal.

When a wound heals, it leaves a scar. A keloid is a special type of scar; one that grows too much and can even become larger than the original wound. It is not uncommon for surgical or injury scars to become a little lumpy (hypertrophic). A keloid differs from these in several ways:

  • A keloid can come up after very minor skin damage, such as an acne spot, or even if there has been no obvious damage to the skin at all.
  • It can spread outside the original area of skin damage.
  • It may last permanently.

KA is a relatively common, rapidly growing skin lesion that usually develops on sun-exposed skin. It arises from skin cells that surround the hair follicle. Early diagnosis is needed to differentiate a keratoacanthoma from a skin cancer called squamous cell carcinoma (SCC) as, unlike an SCC, a keratoacanthoma is benign.  

Keratosis pilaris is a very common and completely harmless skin condition. In the population as a whole, keratosis pilaris may affect as many as one person in three. Its name gives some idea of what it is; ‘keratosis’ means that there is too much keratin, which makes up the tough horny outer layer of the skin, while ‘pilaris’ comes from the Latin for hair (pilus). In keratosis pilaris, many small (1 to 2 mm across) horny plugs can be seen blocking the hair follicles on the upper and outer parts of the arms and thighs. This can look like goose bumps, but feels slightly rough.

Lentigo maligna is one type of the earliest stage of a skin cancer called melanoma.

The word ‘melanoma’ comes from the Greek word ‘melas’, meaning black. Melanin is the dark pigment that gives the skin its natural colour. Melanin is made in the skin by pigment cells called melanocytes. After our skin is exposed to sunlight, the melanocytes make more melanin, and so the skin becomes darker.

Melanocytes can grow together in harmless groups or clusters, which are known as moles. Most people have between 10 and 50 moles and often they are darker than the surrounding skin.

Melanomas can arise in or near to a mole, but can also appear on skin that looks quite normal. They develop when the skin pigment cells (melanocytes) become cancerous and multiply in an uncontrolled way. They can then invade the skin around them and may also spread to other areas such as the lymph nodes, liver and lungs.

Lentigo maligna is a type of melanoma called ‘in situ’ melanoma. ’In situ’ means that the cancer cells have not had the opportunity to spread anywhere else in the body. There are cancer cells in the top layer of the skin (the epidermis) but they are all contained in the area in which they began to develop. They have not started to spread or grow (‘invade’) into deeper layers of the skin. This is why some doctors call in situ cancers ‘pre-cancer’.

Lichen planopilaris is a type of scarring hair loss that occurs when a relatively common skin disease, known as lichen planus, affects areas of skin where there is hair. Lichen planopilaris destroys the hair follicle and then replaces it with scarring. It is between 2 and 5 times more common in women than it is in men and is seen mostly in Caucasian adults, with the commonest age of onset being in the mid-40s. 

Lichen planus is a fairly common (0.2-1% of the population worldwide), itchy, non-infectious rash that usually occurs in adults over the age of 40. In dermatology, the word ‘lichen’ means small bumps on the skin and ‘planus’ means ‘flat’, so the name comes from a description of the rash’s appearance.

Lichen sclerosus is a chronic inflammatory skin condition which can affect any part of the skin, but in females it most often affects the vulva skin and the skin around the anus. It can start in child- or adulthood and affect girls or women of any age.

Lichen sclerosus is a chronic inflammatory skin condition which can affect any part of the skin, but in men is most often seen on the foreskin and tip of the penis. Lichen sclerosus in men does not usually affect the skin around the anus. It can affect boys or men of any age.

In some people, lichen sclerosus also affects the skin elsewhere on the body, where it can cause whitish patches of skin, but usually no discomfort.

The term ‘lichen’ is Latin and means a plant, a moss covering trees. Lichen simplex describes a response of the skin to being repeatedly scratched or rubbed over a long period of time (also called lichen simplex chronicus). A plaque (thickened area of skin) of rough skin forms, with increased markings and sometimes little bumps around hair follicles. There may be only one plaque of lichen simplex or many plaques. 

Lichen simplex can affect any age group, but is most common in adults and unusual in children.

Linear IgA disease is a very rare blistering condition of the skin in adults. A similar condition affecting children is known as Chronic Bullous Disease of Childhood (CBDC).

The condition is called ‘Linear IgA disease’ because a type of protein called  immunoglobulin A (IgA) can be seen deposited under the outer layer of the skin (the epidermis) in a line (linear) when a small sample of skin biopsy is prepared specially and examined under the microscope. 

The lay term for a melanocytic naevus is a “mole”. The word ‘melanocytic’ means that they are made up of the cells (melanocytes) which produce the dark pigment (melanin) that gives the skin its colour. Melanocytes clustered together form naevi. In other words, moles are benign (harmless) groups of melanocytes.

Some moles (congenital melanocytic naevi) are present at birth. Most develop during childhood and early adult life (acquired melanocytic naevi). Almost everyone has moles: many people have between 30 and 50. Many go away in later adult life. Moles can be found anywhere on the skin, including on the hands and feet, genitals, eyes and scalp.

Melanoma is a type of skin cancer, which arises from the pigment cells (melanocytes) in the skin. In a melanoma skin cancer the melanocytes become malignant and multiply excessively. One of the most important causes of melanoma is exposure to too much ultraviolet light in sunlight. The use of artificial sources of ultraviolet light, such as sunbeds, also increases the risk of getting a melanoma.

Melanocytes make a brown/black pigment (known as melanin), and often the first sign of a melanoma developing is a previous mole changing in colour or a new brown/black lesion developing. Most frequently there is darkening in colour but occasionally there is loss of pigmentation with pale areas or red areas developing. This melanoma on the skin is known as the primary melanoma.

Melanoma is considered to be the most serious type of skin cancer because it is more likely to spread (metastasise) from the skin to other parts of the body than other types of skin cancer. If melanoma has spread to other parts of the body, those deposits are known as secondary melanoma (secondaries/metastases).

Stage 1 melanomas are present in the skin only and have not spread elsewhere in the body.

Melanoma is a type of skin cancer, which arises from the pigment cells (melanocytes) in the skin. In a melanoma skin cancer the melanocytes become malignant and multiply excessively. One of the most important causes of melanoma is exposure to too much ultraviolet light in sunlight. The use of artificial sources of ultraviolet light, such as sunbeds, also increases the risk of getting a melanoma.

Melanocytes make a brown/black pigment (known as melanin), and often the first sign of a melanoma developing is a previous mole changing in colour or a new brown/black lesion developing. Most frequently there is darkening in colour but occasionally there is loss of pigmentation with pale areas or red areas developing. This melanoma on the skin is known as the primary melanoma.

Melanoma is considered to be the most serious type of skin cancer because it is more likely to spread (metastasise) from the skin to other parts of the body than other types of skin cancer. If melanoma has spread to other parts of the body, those deposits are known as secondary melanoma (secondaries/metastases).

Stage 2 is considered a thick melanoma present in the skin only.

Melanoma is a type of skin cancer, which arises from the pigment cells (melanocytes) in the skin. In a melanoma skin cancer the melanocytes become malignant and multiply excessively. One of the most important causes of melanoma is exposure to too much ultraviolet light in sunlight. The use of artificial sources of ultraviolet light, such as sunbeds, also increases the risk of getting a melanoma.

Melanocytes make a brown/black pigment (known as melanin), and often the first sign of a melanoma developing is a previous mole changing in colour or a new brown/black lesion developing. Most frequently there is darkening in colour but occasionally there is loss of pigmentation with pale areas or red areas developing. This melanoma on the skin is known as the primary melanoma.

In around 20% of patients diagnosed with melanoma, the melanoma spreads to the lymph nodes. This is classed as stage 3 melanoma.

Lymph nodes, or lymph glands, are found in our lymphatic system which is part of the body’s immune system. The (skin) lymphatics are tiny channels in the skin, which move lymph fluid around the body to the lymph nodes in the groin, under the arms (arm pits) and in the neck. As part of the immune system, the lymph fluid can carry bacteria and even cancer cells with it. Once contained within the lymph nodes, the immune system attempts to destroy them. If the immune system fails to destroy such cancer cells they can grow within the lymph nodes creating a lump. However, the lymph nodes can also swell for other reasons such as infection (e.g. when we have a sore throat there may be swollen glands in the neck).

Melanoma is a type of skin cancer, which arises from the pigment cells (melanocytes) in the skin. In a melanoma skin cancer the melanocytes become malignant and multiply excessively. One of the most important causes of melanoma is exposure to too much ultraviolet light in sunlight. The use of artificial sources of ultraviolet light, such as sunbeds, also increases the risk of getting a melanoma.

Melanocytes make a brown/black pigment (known as melanin), and often the first sign of a melanoma developing is a previous mole changing in colour or a new brown/black lesion developing. Most frequently there is darkening in colour but occasionally there is loss of pigmentation with pale areas or red areas developing. This melanoma on the skin is known as the primary melanoma.

When the melanoma has spread beyond the primary site and the local lymph nodes to other areas in the body, it is known as stage 4 melanoma. Stage 4 melanoma is a form of secondary melanoma where melanoma has spread to distant lymph nodes (glands) or internal organs such as the liver, lungs bones and brain (distant metastases).

Melanoma in situ is the very earliest stage of a skin cancer called melanoma. ‘In situ’ means that the cancer cells have not had the opportunity to spread to anywhere else in the body.

About 7,000 people in the UK are diagnosed with melanoma each year. The word ‘melanoma’ comes from the Greek word ‘melas’, meaning black. Melanin is the pigment that gives the skin its natural colour. Melanin is made in the skin by pigment cells called melanocytes. After our skin is exposed to sunlight, the melanocytes make more melanin, and so the skin becomes darker.

Melasma, also called ‘chloasma’ and ‘pregnancy mask’, is a common skin condition of adults in which light to dark brown or greyish patches of pigmentation develop mainly on facial skin. The name comes from melas, the Greek word for black. It is more common in women, especially pregnant women, and people with darker skin-types who live in sunny climates. However, it can also affect men (10% of patients) and any race. Melasma usually becomes more noticeable in the summer and improves during the winter months. It is not an infection therefore it is not contagious and it is not due to an allergy. It is not cancerous and will not develop into skin cancer.

Mepacrine (an unlicensed drug in the UK of which there are many) was introduced as a treatment for malaria and for certain other tropical infections. It is one of several antimalarial drugs that have been found to also have anti-inflammatory properties, which can help some skin conditions.

Methotrexate is known as a disease-modifying drug. It slows the production of new cells by the body’s immune system (the body's own defence system) and hence reduces inflammation whilst at the same time suppresses the activity of the immune system. It was first used to treat certain types of cancer, and was then found to also be an effective treatment for skin and joint diseases when used at lower doses.

Mohs micrographic surgery is a specialised surgical method for removing certain types of skin cancer. It was first developed by Dr Frederic Mohs in the 1930s.

Traditionally, operations for treating skin cancer surgically have involved removal of the area affected by the skin cancer together with an area of healthy unaffected skin around and below the skin cancer in order to ensure that the entire cancer has been completely removed with suitable margins of excision. Once removed, the skin is sent to the laboratory for examination by a pathologist (a doctor who specialises in medical diagnosis by looking at the cells with a microscope) to confirm whether the operation has been successful or not. It usually takes about 2 weeks for pathology report to become available. If the report shows that the skin cancer has not been fully removed, a further procedure may be necessary.

During the procedure of Mohs micrographic surgery, the skin cancer is removed a thin layer at a time with a small margin of healthy skin surrounding it. Each layer is immediately checked under the microscope by either the surgeon or a pathologist. The layer of skin is examined in horizontal sections. A further layer is taken from any areas in which the tumour remains until all of the skin cancer has been fully removed. The advantage of removing the skin layer by layer in this way is that as little healthy skin around the skin cancer is removed, which keeps the wound as small as possible. Secondly, your dermatological surgeon can be almost certain that the skin cancer is fully removed on the day of the procedure. 

Molluscum contagiosum is a common and relatively harmless viral infection of the skin. As its name implies, it is contagious (can be caught from another person by direct contact). It is most common in children and young adults, but can occur at any age.

Morphoea, also known as localised scleroderma, is uncommon (fewer than 3 per 100,000 people). The word ‘scleroderma’ originates from two words, ‘sclero’ meaning ‘hard’ and ‘derma’ meaning ‘skin’. These are the main feature of morphoea, with areas of morphoea being thicker and firmer than the rest of the skin.

Morphoea should not be confused with systemic sclerosis, in that the damage in morphoea occurs only in the skin, and does not affect internal organs as happens in systemic sclerosis. However, morphoea itself is not one disease with one prognosis. Types of morphoea include: plaque, linear (with a special linear type on scalp called ‘en coup de sabre’), and the generalised type. These types will be discussed later on.

MMP is the most up-to-date term for this condition. Other names include cicatricial pemphigoid, oral pemphigoid and ocular pemphigoid.

MMP is an uncommon blistering condition which most frequently affects the lining of the mouth and gums. Other moist surfaces of the body (known as mucous membranes) can also be affected, and these include the surface layers of the eyes, the inside of the nose, the throat and the genitalia. The skin is sometimes affected by a few scattered blisters. MMP usually starts in middle and old age. Although it is not usually a serious condition in the mouth, the diagnosis of any type of MMP is important as it will alert your specialist to the possibility that the condition may involve your eyes, even if you have no symptoms. Eye involvement (known as ocular cicatricial pemphigoid or ocular MMP) does not occur in all people with MMP, but is potentially serious as it may cause scarring and affect your eyesight.  Scarring may also affect the throat and the genitalia, and may be very serious if the larynx is affected.

Mycophenolate mofetil (MMF) is a very powerful medicine used mainly to stop the body rejecting a transplanted organ (e.g. kidney, heart and liver). However, it is also a useful treatment for a variety of skin conditions. It reduces the action of the body’s own defence system (the immune system) and is one of a group of drugs known as immunosuppressive agents. It is used in certain skin conditions in which the immune system loses control and begins to act against the body.

The name mycosis fungoides is 200 years old and hints, quite wrongly, that it is some sort of fungal infection. In fact it is one of a group of conditions known as cutaneous T-cell lymphoma. Mycosis fungoides is the most common type of Cutaneous T-Cell Lymphoma. A cutaneous T-cell lymphoma is a cancer (an uncontrolled growth) of the T-cell lymphocytes within the skin. (Lymphocytes are a type of white blood cell: they are found in the blood stream and organs, and help to protect us from infections. There are 2 types of lymphocytes: B-cells and T-cells.)

Mycosis fungoides is rare and for many affected people does not affect life expectancy.

Necrobiosis lipoidica is an uncommon inflammatory condition in which shiny, red-brown or yellowish patches develop in the skin, usually in young adults and in early middle age. The condition is most commonly seen in conjunction with diabetes - both the insulin-dependent and non-insulin-dependent types.

‘Pruritus’ is the medical term for itching. ‘Prurigo’ is a related word, which describes the changes that appear in the skin after it has itched and been scratched for a long time. In nodular prurigo these changes take the form of firm very itchy bumps (nodules) on the skin’s surface. These can resolve when the person stops scratching the area, although in many cases this can be very difficult without proper and sometimes prolonged treatment.

Lichen planus is an inflammatory condition of the skin but can also affect the mouth (oral lichen planus). Oral lichen planus may occur on its own or in combination with lichen planus of the skin, nails or genitals. It is thought to affect 1 to 2% per cent of the population, and typically it affects women after the age of 40 years. Oral lichen planus can occur in men but children are rarely affected.

Your body produces corticosteroids naturally, on a daily basis. Without them it would not be possible to survive. Corticosteroids are produced in the cortex of the adrenal glands (hence the ‘cortico-’ part of the name). The ones used most often in medical treatment (prednisolone and dexamethasone) are not exactly the same as the ones produced in the body. It is convenient to refer to them just as ‘corticosteroids’ or 'steroids', but you should be aware that they are different from the type of steroids (anabolic steroids) used for body building. 

The word ‘oral’ means that the steroids are taken in tablet form by mouth. Oral treatment with corticosteroids is also known as ‘oral cortisone therapy’ or ‘systemic steroid therapy’.                  

Palmoplantar pustulosis is a long term (chronic) condition which affects the skin of the palms and soles. It can sometimes occur with the skin condition psoriasis.  

Patch testing is a specialist procedure carried out by dermatology doctors and dermatology nurses to find out whether your skin condition is caused or aggravated by an allergy to substances which have come into contact with your skin. This is called contact allergy.

Substances that cause an allergic reaction are called allergens. They can be found at home, at work or in leisure activities. 

Pemphigoid is a rare blistering disorder, which usually occurs in later life, the average age of onset being over 70 years. The blisters come up on the skin and, less often, in the mouth too. This is in contrast to a related condition known as ‘mucous membrane pemphigoid’ in which the brunt of the trouble is borne by the moist surfaces of the body (the mucous membranes) such as the eyes, inside the nose and mouth, and the genitals.

Pemphigoid gestationis is a rare auto-immune skin blistering disorder that occurs in pregnant women after 13 weeks gestation. It appears with an itchy rash that develops into blisters. It usually recurs in subsequent pregnancies and once triggered tends to occur in women who go on to take oral contraceptive therapy, or rarely during menstruation when periods restart following pregnancy.

Pemphigus vulgaris is a rare autoimmune skin disease. It affects around 3 cases per 100,000 population. Pemphigus vulgaris may cause severe blistering of the skin and the mucous membranes lining the mouth, nose, throat and genital area. Blisters develop in the upper layer of the skin, and have a thin and fragile outer surface that breaks away easily to leave raw areas (erosions) that can be extensive and painful. Pemphigus vulgaris does not go away by itself, and always needs assessment and treatment supervised by a Dermatologist. 

Photodynamic therapy (PDT) is a technique for treating skin cancers and sun-damaged skin which might one day turn cancerous (pre-cancers). In PDT, a special light activates a cream, which was applied to the lesion (affected area of skin). This treatment kills the abnormal cells in the skin.

The term phototherapy literally means the use of light to treat medical conditions. Natural sunlight has been known to be beneficial in certain skin disorders for thousands of years, and it is the ultraviolet part of the radiation produced by the sun that is used in phototherapy, in particular the ultraviolet A (UVA) and ultraviolet B (UVB) wavelengths.

A pilomatricoma is a benign (non-cancerous) growth arising from the cells at the base of hair follicles. It has also been called a pilomatrixoma, trichomatricoma or a ‘calcifying epithelioma of Malherbe’.

Pityriasis alba is a common skin complaint of children and young adults. It appears as pink scaly patches which later leave pale areas on the skin. These pale areas are more noticeable in people with dark skin, and more pronounced after exposure to the sun and the tanning of the non-affected skin. Pityriasis means skin scaling and alba means white.

Pityriasis lichenoides is a rare skin disorder of unknown cause. There are two types of pityriasis lichenoides: an acute form usually found in children known as pityriasis lichenoides et varioliformis acuta (PLEVA), and a more long-lasting form known as pityriasis lichenoides chronica (PLC). 

Pityriasis rosea is a common rash that is usually mild and lasts about 6 to 8 weeks. Its name means that the rash has a fine scale (pityriasis) and it tends to be pink (rosea).

Pityriasis rubra pilaris is the name given to a group of uncommon skin disorders. The name means scaling (pityriasis), redness (rubra) and involvement of the hair follicles (pilaris).  

Pityriasis means a type of fine skin scaling, and versicolor means changing colour. It is a common and harmless rash due to the overgrowth of yeasts that live on everyone’s skin. These yeasts, called Malassezia, are not related to yeast in food or to those that cause thrush. It is also sometimes called tinea versicolor.

Warts are localised thickenings of the skin, and the term ‘plantar warts’ is used for those that occur on the soles of the feet (the ‘plantar’ surface). They are also known as verrucas.

Polymorphic eruption of pregnancy is a relatively common skin disorder that occurs in women of childbearing age. It usually presents in women during their first pregnancy. Recurrence in subsequent pregnancies is unusual (less than 7% of cases) and milder.

The term ‘light eruption’ means a rash that comes up after exposure to light. ‘Polymorphic’ is two words; ‘poly’ means ‘many’, and ‘morphic’ means ‘forms’. In other words, the rash of PLE can take on many different forms, including small red bumps, larger red areas, and blisters. In PLE, a rash with one or more of these components comes up a day or two after exposure to the sun. PLE is common, perhaps affecting up to 10% of the population. It tends to appear in the spring.  

PCT is one of a group of disorders (known as the porphyrias) caused by a range of enzyme defects in one of the biochemical pathways in the body. Any one of these can result in a build-up of chemicals called porphyrins. In PCT the porphyrins are produced from the liver and cause the skin to become very sensitive to light (photosensitive). Some of the other types of porphyria affect internal organs and can cause symptoms unrelated to the skin but this does not happen in PCT.

PCT is an uncommon condition affecting about 1 in 25,000 people. 

A Port Wine Stain is a collection of abnormally formed capillaries in the skin, which results in a red mark that may have the colour of port wine. Although most Port Wine Stains are present at birth, it has been reported in few cases to develop later in life (‘acquired Port Wine Stain’).

Potassium permanganate, when diluted, is a mild antiseptic and astringent (something that dries the skin). It is for external use only.

Important safety advice:

  1. Never swallow or take internally.
  2. Always wearing gloves when handling the Permitabs® to avoid staining or irritant reactions on the fingers.

Propranolol belongs to a group of drugs known as beta-blockers, which are used to treat high blood pressure and fast heart rate. They work by slowing the heart and narrowing blood vessels. This is helpful in haemangiomas, as it reduces the blood flow through them, fading the colour and making them softer. Also, the cells that cause the growth of the haemangioma are affected by propranolol so that the haemangioma starts to reduce in size. Research is under way to find out exactly how propranolol works to reduce the growth and size of haemangiomas.

Pruritus (itching) refers to a sensation of the skin which causes a desire to scratch. Itching is a normal body response to protect us from harmful external substances or parasites such as insect bites. However it can be due to a wide range of skin and internal diseases. Pruritus lasting more than 6 weeks is called chronic pruritus.

‘Pruritus’ means itching. Pruritus ani is itching around the opening of the back passage (the anus). It is a symptom with many causes, but sometimes no obvious cause can be found. Pruritus ani is common and occurs more often in men than women. It is seldom due to an underlying serious condition and those who have pruritus ani are usually otherwise well.

Pseudofolliculitis, also known as ‘shaving bumps’, or ‘razor bumps’, is inflammation of hair follicles and surrounding skin, caused by hairs trapped beneath the skin surface.  It appears similar to folliculitis, which is inflammation of hair follicles due to infection, but the inflammation in pseudofolliculitis is not primarily due to infection. Pseudofolliculitis is typically seen on the face and neck of men who shave, when it may be called pseudofolliculitis barbae, (“barba” being the Latin word for a beard).  It is more common in men of sub-Saharan African lineage, however, can affect men and women of all ethnicities in any body area where hairs are coarse, abundant and subject to shaving, waxing and tweezing.

Psoriasis is a common inflammatory skin disease affecting 2% of the population. It occurs equally in men and women, can appear at any age, and tends to come and go unpredictably. It is not infectious, therefore you cannot catch psoriasis from someone else. It does not scar the skin although sometimes it can cause a temporary increase or reduction in skin pigmentation. Although psoriasis is a long-term condition there are many effective treatments available to keep it under good control.

Treatments that are applied directly to the skin are known as topical treatments. They are the main type of treatment prescribed for most patients with psoriasis. More severe psoriasis may need a variety of other treatments including ultraviolet light or special tablets. Details of these further treatments are given in a separate Patient Information Leaflet: “Treatments for moderate or severe psoriasis”. However, most patients on these further (second line) treatments will still need to continue to use topical treatments.

Patients with psoriasis are usually treated with creams and ointments, which are applied to the skin. These are discussed in a separate leaflet (“Topical treatments for psoriasis”). Sometimes other forms of treatment are needed and this leaflet has been written to help you to understand more about them. It tells you what they are, how they are used, and where you can find out more about them.

Staphylococcus aureus ('SA') is a bacterium (germ) that commonly lives on healthy skin. About one third of healthy people carry it quite harmlessly, usually on moist surfaces such as the nostrils, armpits and groin.

PVL is a toxin produced by certain types of Staphylococcus aureus. The toxin can kill white blood cells and cause damage to skin and deeper tissues.

Pyoderma gangrenosum is a rare treatable cause of skin ulceration. It is not a type of gangrene. Pyoderma gangrenosum is not contagious and cannot be transferred from person to person.

A pyogenic granuloma is a harmless overgrowth of large numbers of tiny blood vessels. It carries no risk of cancer; they are not an infection.

Radiotherapy is the use of X-rays to destroy cancerous cells. In the skin, it is mainly used to treat basal cell carcinomas and squamous cell carcinomas although other conditions may also benefit from the therapy.

Rhinophyma is a swelling of the nose. If the condition progresses, the nose becomes redder, swollen at the end and gains a bumpy surface which changes its shape. This swelling is because there is formation of scar-like tissue and the sebaceous glands (which produce oil on the skin) get bigger. Much more rarely, swellings can arise on other parts of their face such as the ears and chin.

The condition is mainly seen in those who have rosacea, a rash that can affect the cheeks, forehead and nose (see rosacea leaflet for further information). Rhinophyma usually only develops in rosacea which has been active for many years. However, although rosacea affects woman more than men, rhinophyma is seen mainly in fair-skinned men aged 50 to 70 years.

Rosacea is a common rash, usually occurring on the face, which predominantly affects middle-aged (age range 40 to 60 years old) and fair-skinned people. It is more common in women, but tends to be more severe in men. It is a chronic condition and, in any individual, the severity tends to come and go. Rosacea tends to affect the cheeks, forehead, chin and nose, and is characterised by flushing and redness, dilated blood vessels, small red bumps and pus-filled spots (sometimes these may only be visible with a magnifying glass). There may also be uncomfortable inflammation of the surface of the eyes and eyelids.

Sarcoidosis is a disease that can affect just one part of the body, or different parts at the same time. Most commonly it affects the skin, lungs, lymph nodes, or eyes. Less often it can affect the joints, the nervous system, the liver and the kidneys. Sarcoidosis causes a type of inflammation known as a ‘granuloma’, which consists of a cluster of cells that can stop an organ from working properly. For example, granulomas in the lungs can cause breathing problems.

Scabies is a common and very itchy skin condition caused by a tiny mite called Sarcoptes Scabiei. It can affect people of any age but is most common in the young and the elderly.  

‘Dermatitis’ is a red, itchy, flaky (inflamed) skin complaint; ‘seborrhoeic’ means that the rash affects greasy (sebaceous) skin zones such as the face, scalp and centre of the chest.

Seborrhoeic dermatitis is very common and many people don’t even know they have it.  Overall it has been reported to affect about 4% of the population, and dandruff (which is mild seborrhoeic dermatitis of the scalp) can affect almost half of all adults.  It can start at any time after puberty and is slightly commoner in men. Babies can also get a short lived type of seborrhoeic dermatitis in the scalp (cradle cap) and nappy area, which usually clears after a few months.

Seborrhoeic keratoses are also known as seborrhoeic warts, and as basal cell papillomas. Seborrhoeic keratoses are very common harmless, often pigmented, growths on the skin.

Secukinumab is a drug that has been specially designed to mimic normal human molecules, and for this reason it is classed as a ‘biological’ drug. It blocks the activity of a naturally occurring chemical ‘cytokine’ in the body called interleukin-17a (IL-17a). We know that psoriatic plaques contain high levels of IL-17a, and that it drives inflammation in the skin, leading to redness, thickening and flaking.

Shingles is a painful blistering rash caused by the same virus that causes chickenpox, known as the varicella (chickenpox) zoster (shingles) virus.  

Skin camouflage is best described as the application of highly pigmented creams that are designed to effectively mask skin discolouration and scarring. Skin camouflage products mimic normal skin colours and are significantly different from ordinary cosmetics. When correctly applied the products are waterproof, allowing you to swim without the fear of the product washing off. Despite manufacturer’s claims no product is fully “rub-proof”, there may be minor transfer on to clothes, furnishings and bed linen, which can easily be removed by normal household cleansers.

The camouflage is removed daily using a soap substitute (cleansing cream) or toilet soap and water. This allows you to apply topical medication, and emollients, and also to inspect your skin for any changes to the condition.

This leaflet has been written to help you understand and reduce the risk of developing a skin cancer. It is aimed at people at increased risk, such as those who have been previously diagnosed with a skin cancer, or who have significant sun damage to their skin, or those on immunosuppressive drugs, particularly after an organ transplant. It describes the main types of pre-cancerous and cancerous skin growths, and explains the importance of detecting and treating them early. It tells you how to reduce the risk of getting another skin cancer, and how these can be treated.

This leaflet has been written to help you reduce the risk of developing skin cancer in the future after receiving an organ transplant. If you are going to have, or have had an organ transplant, it is important that you take good care of your skin. This is because people having transplants are more at risk of developing skin cancer.

This leaflet has been written to help you understand the risk of developing skin cancer after receiving an organ transplant. It explains the importance of early detection and treatment of skin cancers. It describes the main types of precancerous and cancerous skin growths, how you can reduce the risk of getting skin cancer, and how skin cancer can be treated.

The term ‘solar urticaria’ describes a relatively rare type of urticaria which is triggered by exposing the skin of susceptible individuals to sunlight. Urticaria is also known as hives, weals or nettle rash.

Solar urticaria is found worldwide, and whilst it can start at any age it appears to be those aged between 20 and 40 who are most affected. 

A spider angioma is an enlarged little artery (resembling the body of a spider), from which smaller blood vessels are filled (resembling the spider’s legs). It has also been called several other names, for example ‘naevus araneus’, ‘vascular spider’, ‘arterial spider’, ‘spider telangiectasia’ and ‘spider naevus/nevus’.

Some of these names are Latin: ‘araneus’ for ‘spider’, ‘angioma’ for ‘blood vessel’ and ‘telangiectasia’ for ‘enlarged blood vessel’. 'Naevus’ stands for ‘birthmark’, which is incorrect, as spider angioma are usually not present at birth and develop later.

A squamous cell carcinoma is a type of skin cancer. There are two main types of skin cancer: melanoma and non-melanoma skin cancer. Squamous cell carcinoma (SCC) is a non-melanoma skin cancer (NMSC), and the second most common type of skin cancer in the UK. NMSC accounts for 20% of all cancers and 90% of all skin cancers. SCC accounts for 23% of all NMSC.

Staphylococcal scalded skin syndrome is a widespread painful rash caused by a bacteria called Staphylococcus aureus, which produces a toxin that damages the outer layer of the skin causing it to be shed. 

Lupus erythematosus covers a group of related conditions, all of which can affect the skin and includes systemic lupus erythematosus, a chronic inflammatory disease affecting many systems of the body. However, there are forms of lupus which chiefly affect the skin, such as discoid lupus erythematosus and subacute lupus erythematosus.

Subcorneal (under the top layer of the skin) pustular (pus forming) dermatosis (skin problem) is a rare blistering skin condition. Women get it more often than men (at a ratio of 4:1), and it usually starts after the age of 40.  It may come and go, and can eventually resolve and not require any further treatment. Drs Ian Sneddon and Darrell Wilkinson first described the condition in 1956, which is why it is also called Sneddon-Wilkinson-Disease.

Sweet’s syndrome (also known as acute febrile neutrophilic dermatosis) is a rare skin disorder characterised by a fever and the appearance of tender solid red lumps on the skin. It is a reactive condition with a number of potential triggers. It is not contagious and is not skin cancer.

It is normal to shed approximately 30-150 hairs from our scalp daily as part of our hair cycle. Hair regrows automatically so that the total number of hairs on our head remains constant. Telogen effluvium occurs when there is a marked increase in hairs shed each day. An increased proportion of hairs shift from the growing phase (anagen) to the shedding phase (telogen). Normally only 10% of the scalp hair is in the telogen phase, but in telogen effluvium this increases to 30% or more. This usually happens suddenly and can occur approximately 3 months after a trigger.

Thalidomide was first used in the 1950s as a gentle sedative tablet that can also control severe morning sickness in pregnant women without apparent side effects on the mother. However, after it was discovered to cause severe birth defects when taken in pregnancy, it was withdrawn from use. 

Later, thalidomide was discovered to be helpful for certain skin reactions caused by leprosy (erythema nodosum leprosum), and it was then found to have other beneficial anti-inflammatory effects. This has led to its carefully controlled use in the treatment of some skin disorders for which other medication has not worked. All use of thalidomide must be carefully monitored, with particular attention paid to avoid its use in pregnancy.

Tinea capitis or ‘scalp ringworm’ as it is more commonly known, is the name used to describe an infection of the scalp hair with a type of fungus. Fungi are tiny microscopic organisms that can live on the dead tissue of the hair, nails, and outer skin layer.

It is an infection which occurs most commonly in children; however, it can also occur in adults.

Steroids are naturally occurring chemicals, produced mainly by the adrenal glands in the abdomen. There are different types of steroids, and the type most commonly used to treat skin problems is known as a corticosteroid. Corticosteroids treat skin conditions by suppressing inflammation and reducing the amount of collagen in the skin. Corticosteroids that are applied to the skin in the form of creams, ointments, lotions, mousses, shampoos gels or tapes are known as topical corticosteroids (TCS).

  • Urticaria, also known as hives, is common, and affects about 20% of people (one in 5 people) at some point in their lives. Urticaria consists of pink or white raised areas of skin resembling nettle rash, known as wheals (also spelled weals), which are usually itchy.  The wheals are often round or ring-shaped. Wheals can also appear as lines when the skin is firmly stroked. They can appear anywhere on the skin. Individual wheals typically disappear of their own accord within 24 hours without a trace, although the course of the condition is longer.  
  • Angioedema is characterised by deeper swelling in the skin, which may take over 24 hours to clear. It is not usually itchy and can affect the lips and tongue. Some patients have one or the other condition, others have both.

Urticaria pigmentosa is the commonest type of a group of diseases called cutaneous mastocytosis, which has 3 other different types (see ‘What are the symptoms of urticaria pigmentosa?’ section).

Mastocytosis means increased number of mast cells. Mast cells are a type of blood cell belonging to our immune system, which secrete histamine if triggered. They can exist in the blood vessels or in any body tissue or organ.  Urticaria pigmentosa is composed of pigmented brown patches, made of collections of mast cells that swell when rubbed similar to urticaria. In the majority of cases, urticaria pigmentosa is a harmless condition with excellent outcome.

More than 75% of cases of urticaria pigmentosa happen to infants and children less than 10 years old, but it can also affect older children and adults. It affects both sexes equally and occurs in all races equally. 

Ustekinumab is a drug that has been specially designed to mimic normal human molecules, and for this reason it is classed as a ‘biological’ drug. It reduces skin inflammation by blocking the activity of chemical molecules called cytokines (interleukin 12 and 23) in the body that trigger inflammation in psoriasis.

They are marks made up of excess or abnormal blood vessels in the skin. There are many different types, and only three are described in this leaflet: salmon patches (naevus simplex); port wine stains (naevus flammeus); and strawberry naevi (infantile haemangiomas).

Venous eczema is also known as varicose or stasis eczema and is the name given to a type of eczema on the lower leg. The word eczema (or dermatitis) refers to a common inflammatory skin condition. Venous eczema is more common as people get older and occurs more often in women than in men.

A venous lake is a small blood vessel (vein) in the skin, which over time has become enlarged.

A venous leg ulcer is an open sore in the skin of the lower leg due to high pressure of the blood in the leg veins.

Vitiligo is a condition in which areas of skin lose their normal pigment and become white. It is common, affecting about 1% of the world’s population. 

Vulvodynia means ongoing pain in the vulva (the female genital area) when there is nothing abnormal to see and no known cause for the pain.

Vestibulodynia is a term used for pain arising at the entrance of the vagina, in the area known as the vestibule (the area of the openings to the vagina and the urethra), when any pressure, be it touch or friction, is applied. It is also called localised vulvodynia.

Vulvodynia, whether it is generalised or localised, may be described as provoked (caused by touch) or spontaneous (occurring without touch as a trigger).

Many conditions affecting the vulva can be painful (e.g. infections such as thrush or herpes, as well as skin diseases such as eczema). In vulvodynia, pain is felt in the vulva when there is no obvious visible cause for it and other diagnoses have been ruled out by examination and investigation. 

XP is a very rare condition with about 100 patients living with it in the UK. The genetic material in the skin is unable to repair itself correctly after exposure to ultraviolet radiation (UVR) which is present in all forms of daylight and some artificial light (see section ‘light bulbs’). Without this repair mechanism working correctly a person is much more likely to develop skin cancers of all types. XP can be divided into different types known as complementation groups A to G and Variant. There are slight clinical differences between the groups; some are known to develop neurological problems such as hearing loss, balance problems or learning (cognitive) difficulties. 

Zoon’s balanitis describes inflammation of the head of the penis (glans penis) and foreskin.  It usually affects middle-aged to elderly men who have not been circumcised.

The word Balanitis is derived from the Greek word Balanos, which means ‘acorn’. The ending ‘-itis’ stands for inflammation. Balanitis means inflammation of the glans penis. Zoon’s balanitis is named after Professor Zoon, a Dutch dermatologist, who described the condition in 1952. In addition to the glans penis, the foreskin is often involved.

It has also been called ‘balanitis circumscripta plasmacellularis’ because the patches are well defined, and ‘plasma cell balanitis’ because many plasma cells (a type of white blood cell) may be seen when the affected skin is examined under the microscope. 

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