Derm Dx: Pruritic rashes that run in the family

A 54-year-old woman presented with a 26-year history of intermittent, malodorous, pruritic skin lesions. Several of her relatives have experienced similar rashes.

Past treatments have included oral prednisone, topical steroids, chronic oral doxycycline, and short courses of amoxicillin, cephalexin and cefuroxime, all of which temporarily improved the condition.

Physical examination revealed erythematous eroded scaly papules and plaques in the inguinal ...