A 35-year-old man presented in the emergency room with an erythematous, vesiculo-pustular lesion of the arm near the elbow (see image). One week previously he had scratched his arm on the antenna of his car while washing the windshield. He noticed a red area about three days after the incident, which then spread to involve the adjacent tissue. The central pustule developed on the day he was seen. Material from the center of the pustule was sent to the microbiology laboratory for culture.
