John is a 64 year old male who has developed a post-operative wound following a total hip replacement. John was well prior to surgery and has a history of high cholesterol, which he manages with a good diet. His wound is red, swollen, warm and painful. He also has a fever and feels generally unwell. John is given a broad spectrum antibiotic while waiting for the results on a wound culture. He subsequently experiences an anaphylactic reaction after the second dose of anti-biotics.