An Unusual Side Effect of Azathioprine

The document reports two cases of hair loss as an unusual side effect of azathioprine treatment. The first patient, a 32-year-old woman with severe atopic eczema, experienced excessive hair shedding within 3 weeks of starting azathioprine. She lost hair from her scalp, eyebrows, eyelashes, and body, which continued even after the drug was discontinued, resulting in near-complete loss of scalp hair. However, hair regrowth was observed within 6 weeks of stopping the medication. The second patient, a 46-year-old woman with recurrent lobular panniculitis, also experienced dramatic hair loss within 4 weeks of starting azathioprine, which reversed after the drug was discontinued. Both cases are attributed to anagen effluvium, a condition where hair in the growth phase sheds due to an insult to the hair follicle, commonly seen post-chemotherapy. Azathioprine is known to cause telogen effluvium, but these cases suggest it can also induce anagen effluvium. The authors emphasize the psychological impact of such hair loss and the need for immediate drug withdrawal and supportive measures like wig prescriptions.