A woman in her 80s with a history of diabetes mellitus and a recent arm laceration presented to the emergency department with 1 day of fever, confusion, and a painful, rapidly spreading erythematous area on her arm. Because a necrotizing infection was suspected, treatment with imipenem, clindamycin phosphate, and vancomycin hydrochloride was started. Surgical exploration and debridement confirmed a diagnosis of necrotizing fasciitis. Afterward, she became hypotensive and was admitted to the intensive care unit (ICU). Several operative cultures were positive for group A Streptococcus. The patient underwent 2 additional debridements that week and then was transferred out of the ICU. Treatment with imipenem, clindamycin, and vancomycin was continued for a total of 21 days while she remained in the hospital because of delirium.