Palmoplantar (palmo meaning palm of the hand, plantar meaning sole of the foot) pustulosis is a persistent (chronic) condition which causes blisters filled with fluid on the palms and the soles of the feet. It can sometimes occur with the skin condition psoriasis. 

• Palmoplantar pustulosis - printable version

Patch testing is a specialist procedure carried out in dermatology departments to find out whether your skin condition is caused or made worse 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 may be found both at home and at work.

• Patch testing - printable version

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 - printable version

Pemphigoid gestationis is a rare skin blistering disorder that is associated with pregnancy. It usually presents in mid to late pregnancy (between the 13th and 40th week of pregnancy, known as the second and third trimesters) with an itchy rash that develops into blisters. It may recur in subsequent pregnancies and occasionally recurs in women who go on to take oral contraceptive therapy or during menstruation when their periods restart after pregnancy.

It was previously known as herpes gestationis but this name has been changed as there is no association with herpes virus (cold sore) infection and unlike herpes, pemphigoid gestationis does not spread from person to person.

• Pemphigoid gestationis - printable version

Pemphigus vulgaris is a rare autoimmune skin disease and affects around 3 people per 100,000 population. Pemphigus vulgaris may cause severe blistering of the skin and the mucous membranes lining the mouth, nose, throat, eyes and genital area. Blisters develop in the upper layer of the skin and have a thin and fragile outer surface that breaks away easily leaving raw areas (erosions) that can be extensive and painful. 

• Pemphigus vulgaris - printable version

Peri-oral dermatitis is a common skin condition that more commonly affects women aged 20 to 50 years old. It usually causes persistent redness or small bumps (papules) and sometimes pus containing spots (pustules). It can persist for a few months until the cause is identified and corrected.

The name of the condition ‘Peri-oral dermatitis’can be confusing, as it is not thought to be a form of dermatitis (eczema). Instead, peri-oral dermatitis is thought to be a type of rosacea. Rosacea is a common longstanding condition that causes persistent redness, bumps and pus containing spots (pustules) on the forehead, cheeks, nose and chin. For peri-oral dermatitis, ‘steroid-provoked rosacea’might be a better name, but most people still use the name “peri-oral dermatitis”.

• Peri-oral dermatitis

Photodynamic therapy (PDT) is a technique thatis used to treat certain types of skin cancers such as superficial Basal cell carcinoma and areas of sun-damaged skin (pre-cancerous) that might become cancer in the future. In PDT, a cream is first applied to the area to be treated.  A special light or daylight then activates a cream. This treatment kills the abnormal cells in the skin.

• Photodynamic therapy - printable version

The term phototherapy is a form of treatment where fluorescent light bulbs are used to treat skin 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 of light.

We have produced four leaflets which focus on different types of phototherapy.

Narrowband UVB (NB-UVB) is a particular treatment where a small part of the UVB light spectrum is used to treat the skin condition. Treatment lamps produce these special rays, which has anti-inflammatory effects on the skin. Although these rays are also present in natural sunlight, UVB treatment is usually more effective than sunlight because harmful and ineffective sunlight rays are filtered out. In this way we also seek to minimise the risk of burning episodes.

• NB-UVB Phototherapy - printable version

Oral PUVA therapy is a treatment in which a medication called psoralen (P) is taken by mouth 2-3 hours before exposure of the skin to ultraviolet A (UVA) wavelengths of light. The number of tablets you will take depends on your height and weight and you will be given this medication from the hospital pharmacy. The psoralen reacts in the skin with the UVA to cause effects that help improve or clear a variety of skin conditions. The tablets also make you more sensitive to UVA in sunlight (the rays that get through cloud and window glass) on the days of your treatment.

• Oral PUVA Phototherapy - printable version

Topical PUVA therapy is a treatment in which a medication called psoralen (P) is applied to the skin before exposure of the skin to ultraviolet A (UVA) wavelengths of light. The psoralen can be applied in a variety of ways:

• Bathing the whole body in psoralen solution
• Soaking of parts of the body, for example, hands and feet, in a basin of psoralen solution
• Applying the psoralen preparation in gel form directly on the affected areas

Your doctor will discuss with you the most suitable method of treatment for you. The psoralen reacts in the skin with the UVA to help improve or clear a variety of skin conditions. It also makes you more sensitive to sunlight UVA (the rays that get through cloud and window glass) during the treatment.

• Topical PUVA Phototherapy - printable version

UVA1 means Ultraviolet A. UVA is made up of UVA1 and UVA2. UVA1 is the type of UVA which goes deepest of all into the skin.

• UVA1 Phototherapy - printable version

A pilomatricoma is a benign (non-cancerous) growth arising from the cells at the base of hair follicles. Hair follicles are specialized structures in the skin where hair grows from. Pilomatricoma has also been called a pilomatrixoma, trichomatricoma or a ‘calcifying epithelioma of Malherbe’.

• Pilomatricoma - printable version

Pityriasis alba is a common skin complaint of children and young adults. It appears as pink/pale, scaly patches which later leave pale areas on the skin. These pale areas are more noticeable in people with skin of colour, 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 alba - printable version

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 lichenoides - printable version

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 rosea - printable version

Pityriasis rubra pilaris is a rare long-terminflammatory skin condition. The name means scaling (pityriasis), redness (rubra) and involvement of the hair follicles (pilaris). It affects all races and sexes equally.

It is classified into 6 clinical types:

• Type I is the most common and is called ‘classic adult type’.
• Type II is a variation of type I, known as atypical adult onset.
• Type III, IV and V represent classical, circumscribed and atypical juvenile forms.
• Type VI is associated with HIV-associated PRP (human immunodeficiency virus infection).

• Pityriasis rubra pilaris - printable version

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.

• Pityriasis versicolor - printable version

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.

• Plantar warts - printable version

Polymorphic eruption of pregnancy is a relatively common skin disorder that can occur in women during pregnancy. It usually presents within a women’s first pregnancy. It is characterised by an itchy rash that commonly begins on the abdomen, particularly within stretch marks (striae). It most usually develops during late pregnancy (third trimester) but can also present immediately after the baby is born.

It was previously known as PUPPP (pruritic and urticarial papules and plaques of pregnancy).

• Polymorphic eruption of pregnancy - printable version

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 be more common in the spring.  

• Polymorphic light eruption - printable version

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. 

• Porphyria cutanea tarda - printable version

A Port Wine Stain is a collection of abnormally formed blood vessels (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’). 

• Port wine stain - printable version

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.

• Potassium permanganate solution soaks - printable version

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. The latter 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.

• Propranolol for haemangiomas of infancy - printable version

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, pruritus (or itch) is a common and distressing symptom of many skin diseases, systemic illnesses and psychological disorders.

Itch is perhaps the commonest presenting symptom of skin disorders. In any two week period, 8-9% of the population suffer from significant pruritus. Pruritus lasting more than 6 weeks is called chronic pruritus. Pruritus may be localised to one area or generalized all over the skin.

• Pruritus - printable version

‘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. 

• Pruritus ani - printable version

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.

• Pseudofolliculitis - printable version

Psoriasis is a common skin disease affecting 1 in 50 people. It occurs equally in men and women. It can appear at any age. Psoriasis is a long-term condition which may come and go throughout your lifetime. 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 colour. Although psoriasis is a long-term condition there are many effective treatments available to keep it under good control.

Psoriasis can affect the nails and the joints as well as the skin. Psoriatic arthritis produces swelling and stiffness in the joints or stiffness in the lower back and should be managed by a rheumatologist who works closely with your dermatologist and/or your GP.

Psoriasis, particularly moderate to severe psoriasis, is associated with an increased risk of anxiety, depression and harmful use of alcohol. Moderate to severe psoriasis increases the risk of heart disease and stroke and treatment of psoriasis may reduce this risk. Psoriasis can also be associated with diabetes, obesity, venous thromboembolism, high cholesterol and high blood pressure. Psoriasis is also associated with inflammatory bowel disease and there is a small increased risk of skin cancer.

• Psoriasis - an overview - printable version

A topical treatment is something that is applied directly to the skin or body surface. The commonest examples are lotions, creams, ointments, gels and shampoos. Most people with mild psoriasis are able to manage their skin complaint with topical treatment. Moderate or severe psoriasis usually needs additional   therapy such as ultraviolet or oral (by mouth) medication. See  patient information leaflet “Treatments for moderate or severe psoriasis”.

• Psoriasis - topical treatments - printable version

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.  

• Psoriasis - treatment for moderate or severe psoriasis - printable version

Psoriasis affects about 1 in every 50 people. It can develop at any age – from a baby to an old person. About one third of psoriasis develops before the age of 20 years. Psoriasis is a complicated disease and although the exact cause is not known it seems that many different factors are involved. We know that the way your immune system (the cells designed to fight infection) works is important. In people with psoriasis the immune system is active and the cells in the skin grow faster than normal. All skin has cells that constantly grow and then fall off. This normally takes around 2-3 weeks to happen. In the skin with psoriasis the cells do this very quickly (10 times quicker than normal) which is why the skin becomes scaly.

It can be more likely that you will get psoriasis if someone in your family has it too.

Sometimes injury to the skin or certain infections can cause psoriasis to start or make the psoriasis reappear. Up to half of children or young people with psoriasis will have more psoriasis after infectious illnesses (including colds, throat and ear infections).

It is important to remember your psoriasis is not because you have done something wrong or not done something right.

• Psoriasis in children and young people

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.

• PVL staphylococcus aureus skin infection - printable version

Pyoderma gangrenosum is a rare treatable cause of skin ulceration. Pyoderma gangrenosum belongs to a group of related conditions called neutrophilic dermatoses. Although it sounds similar to gangrene, it is not a type of gangrene. Pyoderma gangrenosum is not contagious and cannot be transferred from person to person.

• Pyoderma gangrenosum - printable version

A pyogenic granuloma is a harmless overgrowth of large numbers of tiny blood vessels on the skin. It carries no risk of cancer, is not contagious (cannot be spread to another person) and is not due to an infection.

• Pyogenic granulomas - printable version

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.

• Radiotherapy for skin cancer - printable version

Rhinophyma is a progressive skin condition that affects the nose. 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). If rosacea progresses, the nose becomes redder, swollen at the end and gains a bumpy surface which changes in 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, swelling can arise on other parts of their face such as the ears and chin.

Rhinophyma usually only develops in rosacea which has been active and untreated for many years. However, although rosacea affects women more than men, rhinophyma mainly affects fair-skinned men aged 50 to 70 years. 

• Rhinophyma - printable version

Risankizumabis a biologic medicine that has been designed to treat psoriasis. It works by specifically targeting a chemical messenger (known as a ‘cytokine’) in the body called ‘interleukin-23’ (IL-23). We know that IL-23 is one of the main causes of inflammation in psoriasis, and by blocking it risankizumab can improve symptoms of psoriasis. 

• Risankizumab - Printable version

Rituximab is a medicine known as a biological therapy or ‘biologic’. It reduces the number of a type of blood cell which defends the body against infection.  These are known as immune cells or B cells. Rituximab does this by binding to a protein called CD20 on their surface. B cells can cause diseases known as inflammatory and autoimmune conditions. B cells do this by producing harmful autoantibodies. Autoantibodies are proteins produced by the immune system against our own tissues and cause inflammation. By removing B cells, autoantibody levels are reduced, and inflammation and its effects can be reduced.

• Rituximab - printable version

Rosacea is a common skin condition, usually occurring on the face, which predominantly affects fair-skinned but may affect all skin types in people aged 40 to 60 years old. It is more common in women but when affecting men, it may be more severe.  It is a chronic condition, and can persist for a long time and, in any individual, the severity tends to fluctuate. Rosacea tends to affect the cheeks, forehead, chin and nose, and is characterised by persistent redness caused by dilated blood vessels, small bumps and pus-filled spots similar to acne There may also be uncomfortable inflammation of the surface of the eyes and eyelids.

Rosacea is classified into 4 subtypes that may overlap. Your doctor will advise you of the type you have.

• Rosacea - printable version

Sarcoidosis is a disease that can affect one or more organs of the body. 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 cause raised lumps on the skin. Having involvement in one part of the body does not necessarily mean it will extend to other organs.

• Sarcoidosis - printable version

Scabies is a common and very itchy skin rash 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. 

• Scabies - printable version

‘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 dermatitis - printable version

Seborrhoeic keratoses (SK) are also known as seborrhoeic warts, and as basal cell papillomas. They are benign growths due to a build-up of skin cells. SK are very common, harmless, often pigmented, growths on the skin. In the UK more than half the men and more than third of women would have at least one SK. By the age of 40 30% of the population would be affected while by the age of 70 it increases to 75%. They are also found in younger people. Some people will have only few seborrhoeic keratoses, while others will have large numbers.

They are not infectious and do not become skin cancer.

• Seborrhoeic keratosis - printable version

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.

• Secukinumab - printable version

Shingles is a painful blistering rash caused by the reactivation of the virus that causes chickenpox, known as the varicella zoster virus.

The virus is called herpes zoster when it causes shingles and herpes varicella when it causes chickenpox. They were named before it was known that a single virus was responsible for both conditions.

• Shingles - printable version

SJS/TEN is a rare, severe skin reaction characterised by a blistering rash in combination with inflammation of the eyes, mouth, nose and genitalia. The upper layer of the skin (called the epidermis) can become detached leaving the lower layer (the dermis) exposed. In adults this is usually a reaction to medication, however in children both infection and medication are important triggers.

• SJS/TEN - PRINTABLE VERSION

Skin camouflage is best described as the application of highly pigmented creams, that are designed to effectively mask skin discolouration and/or scarring. Skin camouflage products are matched to normal skin colour and are significantly different from ordinary cosmetics. When correctly applied, the products are water resistant, allowing you to swim without the fear of the product washing off. Despite the manufacturer’s claims, no skin camouflage product should be considered as totally “rub-proof”; there may be some transfer onto clothing, furnishings and bed linen, which can usually be removed by normal household cleansers.

The camouflage should be removed daily using a soap substitute (cleansing cream) or toilet soap and water. This allows you to inspect the skin for any changes to the condition and allows topical medication and emollients to be applied

• Skin camouflage - printable version

This leaflet has been written to help you understand how to reduce the risk of developing a skin cancer. It is aimed at people with increased risk, such as those who have been previously diagnosed with a skin cancer, 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.

• Skin cancer - how to reduce the risk of getting a second one - printable version

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 in the sun. This is because people having transplants are more at risk of developing skin cancer. 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.

• Skin cancer - information for patients awaiting an organ transplant - printable version

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.

• Skin cancer - information for patients with an organ transplant PIL - printable version

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. 

• Solar urticaria - printable version

A spider angioma is an enlarged blood vessel in the skin (resembling the body of a spider), from which smaller blood vessels extend (resembling the spider’s legs). It has also been called ‘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’ means an increase in normal or healthy tissue within the skin

• Spider angiomas - printable version

Spironolactone is a drug usually prescribed for patients with heart problems, high blood pressure and fluid retention.  It can also have hormonal effects by blocking the action of androgens, “male hormones”, that are normally produced by women in low levels. Some women have raised levels of androgens or increased sensitivity to normal levels of androgens and this can lead to skin disorders.   Spironolactone thus can be used in the management of these conditions. 

• Spironolactone - printable version

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.

• Squamous cell carcinoma - printable version

Staphylococcal scalded skin syndrome is a painful, blistering skin condition which may cover a wide area of skin, caused by a bacteria called Staphylococcus aureus. This produces a toxin that damages the outer layer of the skin causing it to blister and peel. The affected skin initially looks red, resembling a scald or burn and is very tender to touch, which is why the condition is called the staphylococcal scalded skin syndrome. 

• Staphylococcal scalded skin syndrome - printable version

Subacute cutaneous lupus erythematosus is one of a group of related conditions, all of which can affect the skin. The group is called ‘lupus erythematosus’ and the most known subgroup is systemic lupus erythematosus which is a chronic inflammatory disease affecting many systems of the body. If a diagnosis of cutaneous lupus has been made this does not necessarily mean the lupus is systemic, but one of the forms of lupus which chiefly affect the skin. The most common forms of cutaneous lupus are acute lupus, subacute cutaneous lupus and discoid lupus erythematosus.

• Subacute lupus erythematosus - printable version

Subcorneal (under the top layer of the skin) pustular (pus forming) dermatosis (skin problem) is a relatively harmless skin condition where you develop blisters at the skin surface. Women develop the condition more often than men (at a ratio of 4:1) and it usually starts after the age of forty, most commonly presenting between the fifth and seventh decades of life.  It may come and go, and can eventually resolve, not requiring any further treatment.

Doctors Ian Sneddon and Darrell Wilkinson first described the condition in 1956, which is why it is also called Sneddon-Wilkinson disease.

• Subcorneal pustular dermatosis - printable version

Sweet’s syndrome (also known as acute febrile neutrophilic dermatosis) is a rare skin disorder characterised by a fever and the appearance of tender red or purple lumps or patches on the skin that may ulcerate. It is not contagious, not hereditary and not a form of skin cancer.

• Sweet's syndrome - printable version

It is normal to shed approximately 30-150 hairs from our scalp daily as part of our hair cycle, but this can vary depending on washing and brushing routines. 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 the number of 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.

• Telogen effluvium - printable version

Thalidomide was first introduced in 1957 as a sedative tablet that could also control severe morning sickness in pregnant women. When taken in pregnancy, it was associated with severe birth defects from which many babies died across the world. This did not result in any action for several years and it was withdrawn from the UK in 1961. After this tragedy, stronger rules were introduced to improve the safety of medicines.

Thalidomide re-emerged as a therapeutic agent and in 1998 was approved in the USA for treatment of multiple myeloma, a haematological condition.

How exactly thalidomide works is not clear. It appears that thalidomide acts on a part of the immune system and plays a role in wound healing and reduces inflammation. 

• Thalidomide - printable version

Tildrakizumabis a biologic medicine that has been designed to treat psoriasis. It works by specifically targeting a chemical messenger (known as a ‘cytokine’) in the body called ‘interleukin-23’ (IL-23). We know that IL-23 is one of the main causes of inflammation in psoriasis, and by blocking it tildrakizumab can improve symptoms of psoriasis. 

• Tildrakizumab - PRINTABLE VERSION

Tinea capitis or ‘scalp ringworm’ is an infection of the scalp hair and the surrounding skin with a fungus. It is not cause by a worm, despite its name. It is called “ringworm” as it can cause a ring-shaped, scaly, red rash. Fungi are microscopic organisms that can live on the hair, nails, and outer skin layer.

It occurs most commonly in children; however, it can also occur in adults.

• Tinea capitis - printable version

Steroids are naturally occurring chemicals, produced by the body. 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).

TCS are available in different strengths, or potencies: mildly potent, moderately potent, potent and very potent. Your doctor will decide on the correct strength for you on the basis of the nature of your condition, your age and the area of your body being treated. 

• Topical corticosteroids - printable version

Alopecia is a general term for hair loss. Traction Alopecia is a type of hair loss caused by constant pulling (“traction”). The pulling is usually on some hairs more than others leading to the development of bald patches. Often, this type of alopecia is due to  the hairs being pulled repeatedly by  tight hairstyles.

Traction alopecia is a different condition to the one when people have the desire to actively pull their own hair (known as Trichotillomania). 

Traction alopecia can get better when it has only been present for a few weeks or months if the tension applied to the hair is stopped. However, if there is long-term and repetitive pulling on the hair it can lead to permanent hair loss due to damage to the hair follicles, which produce hair.

• Traction alopecia - printable version