Anagen Effluvium in a Child Misusing Methotrexate: A Case Report With Dermoscopic Findings.

Anagen effluvium is a rare adverse effect of methotrexate therapy, generally associated with high-dose regimens. We report a 12-year-old girl who developed abrupt hair loss 1 week after inadvertently taking methotrexate 15 mg daily for five consecutive days (total 75 mg), without other signs of systemic toxicity. Trichoscopic examination and trichogram findings confirmed methotrexate-induced anagen effluvium, and spontaneous hair regrowth occurred after 2 months. This case underlines the importance of careful methotrexate dose monitoring and awareness that methotrexate toxicity can be associated with anagen effluvium even in the absence of other signs of toxicity.