Annular eruption on the lower leg

An otherwise healthy 38-year-old woman presented to the dermatology clinic with a several-month history of a slightly itchy, expanding rash on the lower leg. Treatment with a topical corticosteroid when the rash first appeared helped the itch but seemed to make the rash slightly worse.

Treatment with a topical antifungal several weeks before presentation was also unsuccessful. Examination revealed erythematous pustules ...