Erythema Marginatum

A healthy 3-year-old female child presented to the emergency department with a 1-month history of fevers and rash. The lesions were well-defined with serpiginous margins and involved the back and lower extremities. The child had been initially diagnosed with contact dermatitis and received a topical glucocorticoid without improvement. On examination, the child had arthritis of her left ankle and right knee. Laboratory tests showed normal complete blood counts, and erythrocyte sedimentation rate of 40 mm/hr.

source https://www.jpeds.com/article/S0022-3476(23)00040-9/fulltext?rss=yes