Manifest Hair Repigmentation Associated with Etretinate Therapy

In a letter to the editor, a case was reported where an 82-year-old Japanese man with generalized pustular psoriasis (GPP) experienced manifest hair repigmentation and mild curling of hair texture after being treated with oral etretinate, a medication used for psoriasis and ichthyosiform disorders. The patient, who had mild androgenetic alopecia and had completely white hair for 20 years, noticed darkening of his scalp and eyebrow hair after 1 year of etretinate therapy, which continued to progress over the next 3 years. Trichoscopy confirmed hair repigmentation and some vellus hairs in androgenetic alopecia areas. This case is notable as it is the first to present trichoscopic findings of retinoid-induced hair repigmentation, and it suggests that etretinate therapy may affect melanocyte stem cells and follicular keratinization, leading to changes in hair color and texture. The authors emphasize the need for awareness of potential hair color and texture changes during retinoid treatment with etretinate and acitretin.