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.

The BAD has also prepared a limited number of PILs translations.

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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 backs of the hands and forearms, the face and ears, the scalp in balding men and the lower legs in women. 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. They are usually harmless but there is a very small risk of some actinic keratoses progressing to a form of skin cancer called squamous cell carcinoma (see Patient Information Leaflet on Squamous Cell Carcinoma). 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).

Alopecia is a general term for hair loss. Alopecia areata is a specific, common cause of 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.

Androgenetic alopecia is the most common type of progressive hair loss. It is also known as male-pattern baldness, female-pattern baldness, or just common baldness. It affects about 50% of men over the age of 50, and about 50% of women over the age of 65. In women the severity varies, it may present as widespread hair thinning but in some cases it can lead to complete baldness.

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 as where an individual has a collection of more than 50 moles composed of melanocytes (cells able to produce pigment) present on their bodies, whereby three or more are atypical (unusual) in their appearance, e.g. size and structure. An atypical mole is one greater than 5mm 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 (which is 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 and skin cancer compared to the general population, due to the presence of atypical moles especially if some of these moles are on the scalp, buttocks, or the back of the 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 for more than forty years. It was developed initially to stop rejection of transplanted organs, such as kidneys, although 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 (skin cancer incidence is less than 1%) in the UK. BCC 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’.

Hairs form under the surface of the skin in structures known as hair follicles. A boil is an infection (abscess) of the deep part of a hair follicle with a bacterium called Staphylococcus aureus (S. aureus). Multiple boils are known as a carbuncle. Occasionally, the infection may spread into the surrounding tissues (cellulitis), causing fever and illness.

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 (Protopic 0.03% and 0.1%) and pimecrolimus (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  causing 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 and antiseptics. Such products may make your skin sore and uncomfortable.

Erysipelas and cellulitis are both due to infection of the skin. Erysipelas is a superficial infection of the skin, while cellulitis extends deeper into the tissues. It is often difficult to tell how deep an infection is, so the treatment of cellulitis and erysipelas is the same. These infections can develop quickly and need to be treated with antibiotics as soon as possible; therefore, if you have a recurrence you should seek medical advice as quickly as possible.

Chondrodermatitis nodularis is a localised inflammatory disorder affecting the ears. Literally, this Latin/Greek name 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 painful.

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 fingernails (the nail folds). ‘Acute paronychia’ is the term used for short-lived episodes; ‘chronic paronychia’ is used if it lasts for more than 6 weeks. The condition can last for months or even years.

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. In the UK, colchicine is currently only licensed for the treatment of gout, but is used for many conditions. Colchicine modifies the response of the immune system. It has been found to be helpful in conditions with too many neutrophils (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 ethnic groups. 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 (‘erythro-’) and their formation (‘-poietic’).

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 skin lesions by freezing them. The most common agent used by doctors is liquid nitrogen.

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. 

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 is a very rare type of skin cancer. It usually occurs on the trunk of the body, for example the chest and shoulders, however it can also occur on the limbs and in some cases on the head and neck. It is thought to develop in the deep layer of the skin (the dermis) and can invade deeper tissue such as fat and muscle. Although it grows slowly, it can be quite extensive and can have a high recurrence rate even if removed by surgery. Dermatofibrosarcoma protuberans can, however, be cured if completely removed with a wide margin of normal tissue. Dermatofibrosarcoma protuberans only very rarely 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 the word for inflammation (-itis).

A digital myxoid cyst (sometimes called a mucous cyst) is an entirely benign swelling that occurs on the fingers or, sometimes, the toes. Digital myxoid cysts are not catching and not a sign of infection. Furthermore, they are not cancerous and will not develop into 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 an 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 means disc-shaped, and this name comes from the characteristic round or oval patches which occur in this type of eczema. For the same reason it is sometimes also called “nummular” eczema - nummular meaning coin-shaped.

Discoid eczema is more common in men in their sixties or seventies, although it can occur in women in their teens or twenties. It is uncommon in children; however, this is not exclusive and it can be seen in both sexes at any time in 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 very rare scalp condition. Pus filled spots and lumps develop with subsequent hair loss over the area. Hair loss is permanent due to the development of scar tissue, which destroys the hair follicles.

The condition is occasionally referred to as perifolliculitis capitis abscedens et suffodiens (which means inflammation of the scalp hair follicles and surrounding skin which disappears and digs deep into the skin). It commonly affects black adult men but can affect any race, sex or age.

DSAP is a skin condition causing multiple, dry, ring-like, scaly lesions up to 10 mm each, mainly on the forearms and legs. It is due to the sun 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 more common in women than in men and normally develops between 30-50 years of age. It is not contagious. Very rarely, inherited forms of DSAP can appear in childhood.

Dystrophic epidermolysis bullosa (DEB) is a very 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.

Eccrine porocarcinoma is a rare type of skin cancer involving the sweat glands. Sweat glands are usually found in most regions of the skin. Eccrine Porocarcinoma is typically a slow-growing tumour. However, it can sometimes be aggressive and spread to other 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 skin disorder which causes blistering at sites of rubbing. In the mildest most common 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.

Erythema multiforme is an acute condition which will usually go away on its own but may require treatment for the symptoms.

The name tells you a bit about what the rash looks like. It means a redness (erythema) that is of many (multi-) shapes (-forme). In fact, the rash of erythema multiforme can be recognised by the presence of spots that look like small targets (bull’s eye shaped ‘target lesions’). These have a dusky red centre, a paler area around this, and then a dark red ring round the edge.

Erythema multiforme is usually mild (erythema multiforme minor) – with only a few spots, causing little trouble and clearing up quickly – but there is also a rare but much more severe type (erythema multiforme major/bullous erythema multiforme) that can be life threatening with involvement of the mucus membranes inside the mouth, in the genital area, and on the conjunctiva of the eyes.

Erythema multiforme occurs most commonly between the ages of 10 and 40.  It is rare before the age of 3 or after the age of 50.

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, there is a build up of one of these porphyrins (protoporphyrin) in the blood, especially in the red blood cells. This leads to a sensitivity to sunlight. 

Etanercept 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 can reduce inflammation and affect the immune system (the body's own system of defence). One of its actions in psoriasis is to reduce the activity of a chemical in the body called ‘tumour necrosis factor alpha’ (TNF-alpha). This name is misleading since, apart from attacking tumours, TNF-alpha has many important functions such as fighting infections. There are, however, many diseases in which too much TNF-alpha is produced, causing unwanted inflammation. Etanercept opposes the effects of TNF-alpha.

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 condition of the scalp. Very rarely it can affect other hair-bearing skin. It may be inflamed for a long time and lead to scarring. Folliculitis decalvans is a Latin name meaning inflammation of the hair root associated with hair loss

Folliculitis decalvans is not catching or contagious and is not cancerous.

Fox-Fordyce disease is a disease of the apocrine sweat glands of the skin. The common areas for the condition are the underarms, groin and/or around the nipples. Patients with this condition experience itchy bumps on the skin near to hairs. 

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 a fairly common skin condition, which most often affects children and young adults but can occur at any age.

In most cases, the ring shaped (annular) patches occur on only one or two sites of the body, often on bony areas such as the backs of the hand, elbows or ankles. The patches often consist of groups of small firm bumps in the skin but sometimes they feel quite flat.

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. Most 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.

The hands are the point of contact for many irritants such as soap, detergent, shampoo, water, fibreglass, plasterboard, cutting fluids etc. Frequent contact with irritants, including excessive use of water, reduces skin barrier function and can promote the development of hand eczema or cause the recurrence of pre-existing hand eczema. The hands become red, scaly, cracked, itchy and sore.

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. This can be caught from another person through direct skin-to-skin contact, mouth contact, or sexual contact. The first time the virus is caught, it does not always show up on the skin, but can lie dormant within special parts of the sensory nerves (the sensory nerve ganglia). Later in life, the virus can become active again and appear as herpes simplex 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).

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 essentially means that an individual, usually female, grows too much body or facial hair in a male pattern. Although hirsutism sometimes occurs in males, it is more difficult to detect because of the wide range of normal hair growth in men. Hirsutism affects approximately 10% of women in Western societies and is commoner in those of Mediterranean or Middle-Eastern descent.

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

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 psoriasis 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 licensed for the treatment of malaria, and is one of several antimalarial drugs that have anti-inflammatory effects useful in other diseases. 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 in the summertime. 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 may work in several different ways, such as recognising abnormal cells and causing inflammation to remove them, but the exact mechanism in which the immune system is activated by imiquimod is not yet known.

In the UK, a 5% imiquimod cream is available (trade name Aldara®).

This leaflet has been written to help you understand what immunisations and vaccinations are recommended, and those to avoid, while you are taking medicines that can suppress your immune system.

It also includes a paragraph about immunisations if you are being treated with immunoglobulins.

There are plenty of examples of such medicines, including high dose prednisolone, ciclosporin, methotrexate, mycophenolate mofetil, azathioprine, hydroxycarbamide and new targeted treatments known as ’biological ‘agents e.g. etanercept, infliximab etc.

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. The steroid preparation most frequently used in this procedure is called triamcinolone acetonide, and you may hear the procedure referred to as “intralesional triamcinolone”.

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, marketed by Roche. It works in a variety of ways, targeting several of the factors that cause acne and other skin conditions including production of sebum (an oily substance produced by the skin) and the bacteria that contribute to acne.

Isotretinoin is licensed and most commonly used to treat severe acne, often where there is scarring and pigmentation. Your dermatologist may occasionally use isotretinoin to treat other skin conditions such as hidradenitis suppurativa and rosacea. In the United Kingdom isotretinoin may only be prescribed if you are under the care of a consultant dermatologist.

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, marketed by Roche. It works in a variety of ways, targeting several of the factors that cause acne and other skin conditions including production of sebum (an oily substance produced by the skin) and the bacteria that contribute to acne.

Isotretinoin is licensed and most commonly used to treat severe acne, often where there is scarring and pigmentation. Your dermatologist may occasionally use isotretinoin to treat other skin conditions such as hidradenitis suppurativa and rosacea. In the United Kingdom isotretinoin may only be prescribed if you are under the care of a consultant dermatologist.

Junctional epidermolysis bullosa, also known as JEB, is a rare inherited (genetic) skin disorder. It is different from the other forms of epidermolysis bullosa, known as epidermolysis bullosa simplex and dystrophic epidermolysis bullosa. If you have JEB you 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 sore areas. JEB may be mild, causing little more than inconvenience but it can sometimes be life-threatening. The blisters in JEB appear on birth or early in infancy. Babies affected by the most severe variant of JEB, referred to as Herlitz JEB, 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.

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.
     

KAs are relatively common benign skin growths from the cells surrounding the hair unit that usually appear in sun exposed skin. Clinically they can’t be easily differentiated from a more serious skin cancer, a squamous cell carcinoma (SCC). KAs grow quickly over the first few weeks but do not spread to other parts of the body. If left alone, they will usually go away by themselves in 4 to 6 months.

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’.

Lentigo maligna and melanoma in situ are the very 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 sometimes 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.

‘In situ’ means that the cancer cells have not had the opportunity to spread to 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 into deeper layers of the skin and have not become invasive. This is why some doctors call in situ cancers ‘pre cancer’. The prognosis is excellent.

Lentigo maligna is a type of melanoma in situ. It is a slow growing lesion that appears in areas of skin that get a lot of sun exposure, such as the face or upper body. Because it grows slowly it can take years to develop. Similar to melanoma in situ, lentigo maligna has not spread and is only in the top layer of skin.

Both melanoma in situ and lentigo maligna are cured with surgery. However if not treated with appropriate surgery, they can develop into an invasive cancer. This is why it is important to have them removed with an adequate surgical margin and to know about preventative measures you can take which will lower your risk of these conditions occurring again in the future.

Lichen planopilaris is a type of scarring hair loss that occurs when a relatively common skin disease, known as lichen planus, affects areas of the skin with hair. Lichen planopilaris destroys the hair follicle replacing it with scarring. This is distressing when it affects the scalp. It is twice as common in women as it is in men and seen mostly in adults, with the commonest age of onset being in the mid-40s.

Lichen planus is a fairly common (1-2% of the population worldwide), itchy, non-infectious type of rash that usually occurs in adults over the age of 40 years old. Doctors use the word ‘lichen’ to mean small bumps on the skin. ‘Planus’ means ‘flat’, and tells us that the small itchy bumps that make up the rash of lichen planus have shiny flat tops.

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, although this can be a common area for the problem in women.

It can start in child- or adulthood and 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.

Linear IgA disease is a very rare blistering eruption 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 in a line in the skin when a small sample of skin (a biopsy) is prepared specially and examined under the microscope. This line of IgA lies just under the outer layer of the skin (the epidermis).

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).

Melasma, also called ‘chloasma’, is a common skin condition of adults in which light to dark brown or greyish pigmentation develops, mainly on the face. The name comes from melas, the Greek word for black. Although it can affect both genders and any race, it is more common in women and people with darker skin-types who live in sunny climates. Melasma usually becomes more noticeable in the summer and improves during the winter months. It is not an infection, it is not contagious and it is not due to an allergy. Also, it is not cancerous and will not change into skin cancer.

Mepacrine (an unlicensed drug in the UK) was introduced as a treatment for malaria and for certain other tropical infections. It is one of several antimalarial drugs that have been found also to 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 highly specialised surgical method for removing certain types of skin cancer. It was developed by Dr Frederic Mohs in the 1930s.

Traditionally, operations for treating skin cancer have involved removal of the affected area (also known as a tumour), along with an area of healthy skin around and below it in order to ensure that the entire cancer has been fully removed. Once removed, the affected area is sent to the laboratory for examination by a pathologist (a doctor who specialises in medical diagnosis by looking at tissue cells under the microscope) to confirm whether the operation has been successful or not. It may take about 2 weeks for the report to become available. If the report shows that the cancer has not been fully removed, a further procedure may be necessary.

With Mohs micrographic surgery, the skin cancer is removed a thin layer at a time with a very small margin of healthy skin around it. Each layer is immediately checked under the microscope by either the surgeon or pathologist. The layer of skin is examined in horizontal sections, which is a very accurate way of telling if the tumour has been fully cut out. A further layer is taken from any areas in which the tumour remains, if necessary, until all of the skin cancer has been fully removed. This allows for removal of as little healthy skin around and below the cancer as possible, which keeps the wound as small as possible. This makes it 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.

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. A cutaneous T-cell lymphoma is 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 the quality of life or life expectancy.

Necrobiosis lipoidica is an uncommon inflammatory condition in which shiny, red-brown or yellowish patches develop in the skin, usually on the shins. Its significance is that it is often associated with underlying 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 will resolve when the person stops scratching the area, although in many cases this can be very difficult without proper treatment.

Lichen planus is an inflammatory condition of the skin (see PIL on Lichen Planus) but can also affect the mouth (oral lichen planus) and genital region. Oral lichen planus may occur on its own or in combination with lichen planus of the skin or genitals. It is thought to affect 1-2% of the population. Oral lichen planus predominantly occurs in adults older than 40 years, although younger adults and children can be affected. The female-to-male ratio for oral lichen planus is 1.4:1.

Oral pemphigoid (pemphigoid of the mouth) is an uncommon blistering condition which affects primarily 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, inside the nose and the genitalia. The skin is less commonly involved but can be affected by a similar blistering condition, known as bullous pemphigoid.

Your body produces corticosteroids naturally, on a daily basis. Without them it would not be possible to survive. Corticosteroids are made 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 (mainly hydrocortisone). 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 power building (which are correctly termed androgenic steroids).

Palmoplantar pustulosis is a chronic condition which can affect the palms of the hands and soles of the feet. It may occur with psoriasis or without any other skin disease.

Patch testing is a specialist procedure carried out by dermatology clinicians. It can help your referring doctor find out whether your skin condition is caused by an allergy to substances (these substances are called allergens) which come into contact with your skin, such as products at home, at work or in leisure activities. You can then be advised of the names of any identified allergens in order to help you to avoid them.

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 disease (up to 3.2 cases per 100,000 population) that causes severe blistering of the skin and of the mucous membranes lining the mouth, nose, throat and genitals. Blisters are sacs with fluid that develop on the upper layer of the skin so their roofs are very thin and fragile, and break easily to leave raw areas (erosions) that can be extensive and painful. Pemphigus does not go away by itself, and always needs treatment 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 has been 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, especially ultraviolet 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 lichenoides is a rare skin disorder that is limited to the skin. The term ‘pityriasis lichenoides’ means that the rash is scaly (pityriasis) and that it was once thought to look like a lichen (a type of plant that lives on rocks) because it is made up of small bumpy areas. 

Pityriasis rosea is a common and harmless rash that goes away by itself after about 8 weeks. Its name means that the rash is scaly (pityriasis) and pink (rosea).

Pityriasis rubra pilaris is the name given to a group of uncommon skin disorders that look rather similar, but which are probably different conditions. Their name means that they share some of the same features, e.g. 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.

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’).

Propranolol belongs to a group of drugs known as beta-blockers, which are used to treat high blood pressure and fast heart rates. 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. More research is happening 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 is inflammation caused by cut hairs growing back into or under the skin surface. It is not due primarily to infection, but does look rather like the spots caused by inflammation of hair follicles due to infection (folliculitis). Pseudofolliculitis is usually 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), but it can occur in other body regions that are shaved, in both men and women. It is also known as ‘shaving bumps’, or ‘razor bumps’. 

Psoriasis is a common skin problem affecting about 2% of the population. It occurs equally in men and women, at any age, and tends to come and go unpredictably. It is not infectious, and does not scar the skin.

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.

PVL is a toxin produced by certain types of the bacteria Staphylococcus Aureus. PVL-SA can kill white blood cells and cause tissue damage.

Pyoderma gangrenosum is a rare treatable cause of skin ulcers. It is not related to gangrene. Pyoderma gangrenosum is not contagious and cannot be transferred from or to another person by touching or in any other way.

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 both middle-aged (age range 40-60 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 the severity tends to come and go. Rosacea tends to affect the cheeks, forehead, chin and nose, and is characterised by redness, dilated blood vessels, small red bumps and pus-filled spots, often with a tendency to blush easily.

Sarcoidosis is a relatively uncommon 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 frequently it can affect the joints, the nervous system, the liver and the kidneys. Sarcoid 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 human scabies mites. It can affect people of any age but is most common in the young and the elderly.

‘Dermatitis’ means an inflammation of the skin; ‘seborrhoeic’ simply means that the rash commonly comes up in areas rich in sebaceous (grease) glands such as the face, scalp and centre of the chest. Seborrhoeic dermatitis is very common, affecting between 3 and 5% of the global population. It is more common in young adults than during old age and can occur in infants, but then it usually clears up over 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.

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 induced by exposing your skin to sunlight. It is a useful term as it reminds us of the main features of the condition; ‘solar’ describing that it is caused by light from the sun and ‘urticaria’ describing that the rash produced on the skin. Urticaria is also known as hives, weals and 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, and the second most common type of skin cancer in the UK.

Staphylococcal scalded skin syndrome is a widespread painful rash caused by bacteria called Staphylococcus aureus. This germ produces a toxin that causes the outer layer of the skin to be shed. 

Lupus erythematosus covers a group of related conditions, all of which can affect the skin. It 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 an uncommon skin disorder characterised by a fever and the appearance of tender red lumps on the skin. It is a reactive condition with a number of potential triggers. It is not contagious and cannot be transferred from one person to another.

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.

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 is common, affecting about 20% of people at some point in their lives. It is also known as hives or nettle rash. The short-lived swellings of urticaria are known as weals and typically any individual spot will clear within 24 hours although the overall rash may last for longer. Angioedema is a form of urticaria in which there is deeper swelling in the skin, and the swelling may take longer than 24 hours to clear. An affected individual may have urticaria alone, angioedema alone, or both together.

Urticaria pigmentosa is the commonest clinical form of a group of conditions known collectively as ‘cutaneous mastocytosis’, in which mast cells are present in abnormal collections in some or many areas of the skin. Cutaneous Mastocytosis is one form of a group of diseases called Mastocytosis, where mast cells also affect other organs of the body. Mast cells are a type of cell characterised by containing a number of inflammation-provoking chemicals, which include histamine.

Ustekinumab 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 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 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 pain in the vulva, the female genital area. 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. 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 a touch or friction, is applied. As with vulvodynia, there is no obvious visible cause for the pain in vestibulodynia.

Zoon’s balanitis describes a form of chronic inflammation of the glans penis and foreskin, which affects uncurcumcised middle-aged to elderly men. The word Balanitis is derived from the Greek word Balanos, which means ‘acorn’. The ending ‘-itis’ stands for inflammation. Balanitis therefore 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.

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