Alopecia Areata Caused by an Adverse Reaction to Denosumab

A 67-year-old woman experienced patchy hair loss, diagnosed as alopecia areata, after starting treatment with denosumab for osteoporosis. Despite initially suspecting simvastatin, the hair loss persisted after stopping the statin. Examination showed nonscarring hair loss with exclamation-mark hairs, and treatment with intralesional triamcinolone led to good hair regrowth. Denosumab, a monoclonal antibody, may cause alopecia areata, similar to other biologic drugs. The mechanism is not fully understood, but this case highlights the need to consider denosumab as a potential cause of alopecia areata in patients.