Clinical course of alopecia areata

The clinical course of alopecia areata (AA) is unpredictable. Up to 50% of patients will recover within a year without treatment. However, the majority of AA patients will show an irregular relapsing-remitting course, with multiple episodes of hair loss. The major prognostic factors with clinical relevance include the extent and duration of disease. Many therapeutic options exist for AA and the recommended treatment strategies are based on the age of the patient and the extent of disease. Therapeutic modalities include topical minoxidil, topical and intralesional corticosteroids for mild AA, and diphenylcyclopropenone (DPCP) for severe AA. Unfortunately, to date, there is no approved cure that provides complete hair regrowth, and all treatments are considered "off-label". For many reasons, including a high rate of spontaneous remission and paucity of randomized-controlled studies investigating treatment efficacy, it is difficult to assess therapeutic effects for AA. Moreover, long-term follow-up is not reported in many of the publications. Another important drawback is the great variation in treatment outcome evaluation. To niinimize this factor, the Severity of Alopecia Tool (SALT) score has been used as a method for measuring the extent of scalp AA. Recently, we introduced the Alopecia Areata Progression Index (AAPI) which seems to represent a system capable of quantifying overall hair loss activity in AA patients with different severity. In this review, we discuss the clinical course, prognosis, evaluation of treatment, and measuring tools of AA.