Severe Alopecia caused by Azathioprine in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder with heterogeneous phenotypes. The symptoms range from mild to life-threatening features. Azathioprine (AZA) is a routinely used immunosuppressive agent in mild to moderate SLE. Although bone marrow suppression is reported in AZA usage, severe alopecia is not very common with AZA.

We report a 45-year-old female with stable clinical and serological lupus maintained on mycophenolate mofetil 500 mg twice per day and hydroxychloroquine 200 mg once per day. She was lost to follow-up with us for >1 year. Since her disease was stable, we switched to AZA 25 mg twice per day to start with and escalated to 50 mg in the morning and 25 mg at night after 2 weeks, with an advice for 4-week follow-up after starting AZA. Hydroxychloroquine was continued at 200 mg once per day. No corticosteroids were used at this time as it was not deemed necessary. Monitoring blood tests for AZA were planned at 4 weeks. She presented at 6 weeks with severe leukopenia as summarized in the table of investigations below and the graph summarizing the trend in leukocyte counts after AZA usage. She was managed in the hospital with intravenous dexamethasone, antibiotic prophylaxis, and hematology consultation, who opined as AZA-induced severe bone marrow suppression and severe alopecia due to AZA. Bone marrow examination was not deemed necessary by the hematologist. AZA was stopped in the hospital and mycophenolate mofetil was prescribed in the immediate follow-up after discharge, as she had previously responded to this drug. Hydroxychloroquine continued throughout her hospital stay. Although her blood counts responded very well after AZA withdrawal, it took nearly 3 months for her to have her normal scalp hair. One of the major differentials that was considered was SLE flare-up, but her clinical features and serology did not support a lupus flare.

Bone marrow suppression is a severe complication of AZA in SLE. Leukopenia and hair loss are the major adverse effects reported during the therapy of AZA. It is sensible to recognize this relationship as prompt diagnosis and treatment is crucial.