Concomitant acute alopecia and profound bone marrow suppression: An unusual manifestation of azathioprine toxicity

Abstract

Azathioprine is a cytotoxic drug used frequently as a steroid-sparing agent in multiple dermatological diseases. Myelosuppression is known to occur with azathioprine, but severe pancytopenia and hair loss are uncommon. Hair loss usually occurs with long-term use, but sudden onset and rapidly progressive alopecia are extremely rare. In this report, we present an unusual case of a patient with chronic spontaneous urticaria, accompanied by elevated serum immunoglobulin E levels, who developed sudden-onset, rapidly progressing alopecia areata concurrent with azathioprine-induced bone marrow suppression. The patient’s condition improved following discontinuation of azathioprine, with concurrent resolution of leukopenia and gradual hair regrowth, suggesting a temporal and possibly causative relationship between the drug and both the hematologic and dermatologic manifestations. This case emphasizes the unpredictable nature of immunomodulatory therapy and highlights a paradox wherein a drug intended to suppress autoimmune activity potentially triggers a separate autoimmune condition. It also emphasizes the importance of vigilant monitoring for both common and rare adverse effects during azathioprine therapy.