The term alopecia means hair loss. In alopecia areata, round bald patches appear suddenly, most often affecting the scalp. It is a form of autoimmunehair loss.

Alopecia areata can occur at any age, including in childhood.

Alopecia areata is considered to be one of the autoimmune disorders – lymphocytes aound the hair follicles release chemical messengers (called cytokines) that reject the hair for unknown reasons.

Alopecia areata may occur in more than one member of the family, and such families may develop other autoimmune diseases such as pernicious anaemia andvitiligo. It is also more common in patients with chromosomal disorders such as Down syndrome.

Like many other health problems, it sometimes starts after a stressful event. Alopecia areata itself ma

Unfortunately there is not yet any reliable cure for alopecia areata and other forms of autoimmune hair loss. Luckily the hair usually grows back slowly by itself. Sometimes the new hair may regrow grey or white, but after a while the original colour usually returns.

Injecting a corticosteroid such as triamcinolone acetonide 2.5–10 mg/ml into the area of hair loss may speed up the natural regrowth of hair. This treatment is known as an ‘intralesional steroid injection’. The regrowth occurs only in the area that has been injected. There is no way of preventing new areas of hair loss. However if they appear, regrowth can be helped by further injections.

The most successful treatment to date has been immunotherapy. Immunotherapy works by provoking a contact allergic dermatitis in affected areas by applying a low concentration of a material to which the patient has been made allergic. This is most often diphenylcyclopropenone (diphencyprone). Unfortunately the resultant dermatitis is irritating and may be unsightly, often accompanied by a swollen lymph gland. Therapists and others in contact with the diphencyprone can also develop dermatitis.