Drug-induced alopecia

Drug-induced alopecia is suspected when hair loss begins after starting, increasing or switching a medication, once more common causes have been considered. It may present as diffuse shedding, anagen effluvium, pattern-like thinning or hair shaft changes, depending on the medicine. Examples reported in the literature include some anticoagulants, retinoids, antithyroid drugs, anticonvulsants, beta-blockers, antidepressants, chemotherapy and hormonal therapies. The key diagnostic clue is timing, but medication should not be stopped without medical advice.