REPORT OF A CASE
A 37-year-old Hispanic woman presented to the emergency room with a 4-day history of a progressive rash on the left leg. The eruption began as a red papule and expanded centrifugally. There was no history of trauma. The patient also complained of pain in her left shoulder and in several fingers. Although she denied fever during the examination, she did admit to a history of fever and sore throat 1 to 2 weeks before. She was otherwise in good health and was taking no medications.On examination, the patient had a 5- to 10-cm warm, indurated, erythematous plaque with indistinct borders on the left lower shin (Figs 1 and 2). There was no drainage or epidermal change. The remainder of the examination was unremarkable. There was no adenopathy or joint swelling. Laboratory examinations showed the following results or values: leukocytes, 21×109/L; erythrocyte sedimentation rate, 80 mm/h;