ABSTRACT
Alopecia areata (AA) accounts for up to 2% of new dermatological outpatient attendances in the UK and USA. It is not at present possible to attribute cases of AA to a single cause. Among the many factors that appear to be implicated are the patient’s genetic constitution, the atopic state, non-specific immune and organ-specific autoimmune reactions, and possibly emotional stress. The process can be inhibited to a variable extent by several very different therapeutic measures: corticosteroids, local irritants, photochemotherapy, induction of contact dermatitis, or oral ciclosporin. The different chemistries and modes of action of these therapies have opened new channels of research. However, recent studies have done no more than reinforce the generally held belief that both genetic predisposition and the atopic state influence prognosis, but the triggering mechanisms remain obscure.
