Drug hypersensitivity is an abnormal reaction of the immune system to a medication. This can lead to various symptoms, ranging from mild skin rashes to severe reactions like anaphylaxis. The exact cause of drug hypersensitivity can vary, but it often involves the immune system mistakenly identifying a drug as harmful. Common medications that can cause hypersensitivity include antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), and anticonvulsants. Diagnosis typically involves a detailed medical history and sometimes skin tests or blood tests. Management includes avoiding the offending drug and, in severe cases, using treatments like epinephrine for immediate relief.