Tinea Incognito Misdiagnosed as Erythema Migrans

To the Editor: A 12-year-old girl presented to her primary care physician with a 6-cm circle of erythema with central clearing on the side of her neck. The patient lived in an area of Connecticut where Lyme disease is endemic. Her physician diagnosed erythema migrans and prescribed amoxicillin (500 mg three times a day for 20 days). After 20 days of antibiotic therapy, the rash had enlarged and contained multiple rings (Figure 1). Her physician thought she had erythema migrans that was unresponsive to amoxicillin therapy. The eruption was mildly pruritic, and the patient had no constitutional symptoms. At this . . .