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. About three days after the incident, he noticed a red area that 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.
