Methotrexate

A 35-year-old woman developed trichostasis spinulosa of terminal hair after using topical 2% minoxidil for 13 years to treat female pattern hair loss. She had been applying minoxidil not only to her crown area but also to her high frontal and temporal regions to prevent hair loss. Upon examination, she showed signs of mixed pattern androgenetic alopecia and multiple follicular hair bristles on her temples and frontal hairline. Dermoscopy revealed pigmented terminal hair tufts in each hair follicle, and a biopsy indicated a terminal hair follicle with a dilated infundibulum containing hyperkeratotic material and detached hair shafts within a keratinous sheath. The authors suggested that the trichotrophic agent minoxidil might have induced the transformation of vellus hairs into more conspicuous terminal hairs, leading to trichostasis spinulosa. The patient's outcome was not reported.