A 47-year-old fishmonger presented with a history of weight loss and lethargy. On investigation he was found to have myeloma. He presented again before follow up, with a 3-day history of fever and a maculopapular rash. He was admitted to the haematology ward and treated with broad-spectrum antibiotics. Blood cultures were found to be positive for Erysipelothrix rhusiopathiae. Penicillin treatment was given, and he made a good recovery. The importance of occupational illness in an already immunocompromised patient and of taking a proper social and occupational history from patients on admission is illustrated through this case.