Furosemide
January 2009
in “
Reactions Weekly
”
TLDR A man had an allergic skin reaction on his penis from a hair loss medication, which improved after stopping the medication.
In 2009, a 39-year-old man developed a fixed drug eruption, a type of allergic skin reaction, on his penis shaft after taking oral finasteride (1 mg/day) for androgenic alopecia. The duration from when he started the medication to the onset of the reaction was not specified. Despite using topical steroids, the eruption persisted. A skin biopsy showed lymphocytic and eosinophilic infiltrates and melanophage deposits, leading to the suspicion of a fixed drug eruption. After discontinuing finasteride and restarting topical steroids, the erythema resolved but left mild pigmentation. Skin patch tests with finasteride were negative, but an oral rechallenge with the drug reproduced the lesion. This was the first reported case of a fixed drug eruption caused by finasteride, with no previous cases found in AdisBase, Medline, Embase, or the WHO Adverse Drug Reactions database, which only contained two reports of fixed eruption associated with finasteride.
