A – Z of Skin

Information for Skin, Hair and Nail Conditions


The A to Z of Skin information has been developed to help you understand more about common skin conditions and problems, and how these may be treated.

Both common and medical names have been included to help your search, as well as the names of medications and treatments. There are also a number of cosmetic topics which explain the latest treatments for cosmetic concerns related to the skin. Many College dermatologists have contributed to the information on this site.

The process has been overseen by a committee of dermatologists to ensure that the final versions are both accurate and user friendly. Particular thanks go to Dr Pam Brown, Dr Peter Berger, Dr Davin Lim, Dr Michelle Rodrigues, Dr Yin Vun, Conjoint Associate Prof Orli Wargon and Dr Eleni Yiasemides (Chair). The A to Z information is currently under development. Please check back on a regular basis for updates and the addition of new topics.

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  • Dapsone

    Dapsone is a tablet taken for several and varied dermatological conditions. The dose varies between 50 and 200 mg a day taken all at once. The duration of treatment will depend on the progress made and can vary from months to several years.

  • Darier’s Disease

    Darier’s disease is a rare, genetic disorder which causes a decreased and abnormal sticking together of skin cells and results in a variety of changes including irritating greasy crusted lumps on the skin and nail changes.

  • Deep gyrate erythema

    Deep gyrate erythema also known as erythema annulare centrifugum (EAC), refers to an annular (ring-shaped) erythematous (red) skin eruption that tends to spread outwards whilst clearing centrally.

  • Degos Disease

    Degos disease is a rare progressive condition affecting blood vessels. This causes disease in the skin, gastrointestinal tract and central nervous system.

  • Delusions of parasitosis

    Delusions of parasitosis is a rare and very distressing psychiatric disorder. The person suffering from the condition truly believes that their skin is infested by parasites (mites, lice or other insects). However, when the skin is examined, no parasites or bugs can be seen in or on the skin.

  • Dermatitis herpetiformis

    Dermatitis herpetiformis is an uncommon itchy skin condition which can occur at any age. It is a specific skin change seen in coeliac disease.

  • Dermatitis Papillaris Capillitii

    Dermatitis Papillaris Capillitii also known as Acne keloidalis nuchae (AKN) is a chronic inflammatory condition that affects hair follicles on the back of the neck. AKN is most commonly seen in men of African-Caribbean background but it is also seen in those of Hispanic, Asian, Middle Eastern and Mediterranean backgrounds. In rare cases, it may also be see in Caucasians. Whilst this condition mostly affects men, women may be affected in some cases (the ratio of  affected men to women is 20:1). The term AKN is misleading because the condition does not form true keloid scars and is not associated with acne.

  • Dermatitis/Eczema

    Dermatitis is a general term to describe a group of common conditions presenting as itchy inflammation of the skin. The term eczema is often used interchangeably with dermatitis although theoretically eczema refers to atopic eczema. There are a variety of clinical types and causes.

  • Dermatomyositis

    Dermatomyositis is a condition where there is inflammation in skin, muscles and blood vessels. The condition is more common in females. It can affect children usually before the age of 10 years as well as adults usually over the age of 40 years.

  • Dermatosis Papulosa Nigra (DPN)

    Dermatosis papulosa nigra (DPN) is a benign (harmless) condition where multiple small, brown-black, raised spots appear on the face and neck. DPN is seen most commonly in people with coloured skin (skin of colour) who are of African, Asian, Indian, or Polynesian background. DPN may be considered as cosmetically undesirable

  • Digital myxoid cysts

    A digital myxoid cyst is an entirely benign, non-cancerous swelling that usually occurs at the base of the nail on the fingers or toes. Digital myxoid cysts are not “catching” and they are not a sign of infection. They do not develop into skin cancer.

  • Discoid eczema

    Discoid eczema is a common type of eczema or dermatitis with coin-shaped areas of inflammation on the limbs or torso. It is usually very itchy.

  • Dissecting cellulitis of the scalp

    Dissecting cellulitis of the scalp is a rare condition in which pus-filled lumps develop on the scalp, resulting in scarring and permanent hair loss over the area affected.  

  • Drug eruptions & reactions

    Drug reactions are unwanted and unexpected reactions occurring in the skin (and sometimes other organ systems) that may result from taking a medication for the prevention, diagnosis or treatment of a medical problem. They may appear after the correct use of the medication or drug.

  • Dry skin

    Dry skin also known as Xerosis is a common condition which occurs when the outer layer of the skin becomes dehydrated. The skin loses its suppleness and small splits and/or cracks appear, followed by flaking or scales.

  • Dyshidrotic eczema

    Dyshidrotic eczema also known as pompholyx, is an often recurrent and frequently extremely itchy disorder characterised by tiny blisters and bumps on the sides of fingers, toes, palms and soles.

  • Dystrophic epidermolysis bullosa

    Dystrophic epidermolysis bullosa (DEB) is one of the main types of epidermolysis bullosa (EB). This group of inherited skin fragility disorders is characterised by blistering of the skin and body linings with minimal injury.