Outcome of treatment with azathioprine in severe atopic dermatitis: a 5-year retrospective study of adult outpatients

Funding sources: None. Conflicts of interest: None declared. Dear Editor, Azathioprine is one of several immunomodulatory drugs used in the treatment of severe atopic dermatitis (AD).1 Two double‐blinded, randomized, placebo‐controlled trials (n =37 and n =63, respectively)2 3 and one single‐blinded, randomized, controlled trial comparing azathioprine with methotrexate (n =42)4 have evaluated the efficacy and safety of azathioprine in patients with AD. These studies indicate that azathioprine is superior to placebo and with a clinical efficacy equal to that of methotrexate in controlling AD with an expected average reduction in disease activity of about 40%. Furthermore, these studies have shown that adverse effects, particularly gastrointestinal (GI) disturbances, are common with azathioprine, accounting for premature discontinuation of treatment in about 30% of patients. There are no definite recommendations for the duration of treatment of AD with azathioprine,5 and data on long‐term adherence and on the causes for discontinuation of azathioprine for this indication are lacking.