Alopecia areata is a common condition characterised by sudden onset of patchy hair loss without signs of skin inflammation or scarring. It accounts for about 2% of new referrals for dermatology in the UK and United States and has an estimated lifetime risk of 1.7%.1 Data from the National Health and Nutrition Examination Survey indicated a prevalence of 0.15% in the population of the United States.^w1 The extent of hair loss can vary greatly, ranging from a single coin sized patch to very extensive alopecia involving the entire scalp and the rest of the body. The condition is unpredictable; spontaneous regrowth of hair can occur at any time during its course with the possibility of subsequent relapse. Alopecia areata is particularly difficult to manage and most of the available therapeutic options are unsatisfactory. It is a psychologically distressing disease and doctors should provide patients with realistic advice about treatments and their effectiveness.

Although several medical treatments have been reported for the condition, the evidence is quite difficult to interpret because of differing study methods, non-homogeneous patient populations, variability in outcome measures, and failure to control for spontaneous regrowth. A recent Cochrane …