(From BMJ 31.7.2010 – I’m working my way through some old ones I didn’t make notes on at the time)
Alopecia areata is an auto-immune disease, often associated with others such as vitiligo and thyroid disease. Prognosis is variable – of those with patchy disease, around half will have spontaneous remission within a year (although many of those will have recurrences), but around 30% will eventually go bald. In patients with extensive disease, unfortunately less than 10% will have a sustained remission. Factors associated with poor prognosis are onset before puberty, co-existing atopy or other autoimmune diseases, nail dystrophy, family history, and long disease duration. One point to note about the good rates of spontaneous remission is that they do make it difficult to assess the efficacy of treatments (on a practical note, however, the disease does lend itself beautifully to within-patient research comparisons, by dint of half-head studies).
So far, the best treatment for patchy loss appears to be intralesional steroid injection, and the best treatment for extensive disease is topical immunotherapy. I noticed that Minoxidil is now being sold over the counter at vast cost so looked to see what it had to say about that – apparently the evidence is conflicting and not hugely convincing, so I should probably tell patients to save their money.