Hypersensitivities to non-steroidal anti-inflammatory drugs.

NSAIDs are the most commonly used medications worldwide and are responsible for almost 25% of adverse drug reactions. Such reactions can have different manifestations and can be immunologic or non-immunologic. The diagnosis is primarily based on the medical history, which can be difficult in patients receiving multiple medications. Because skin testing and blood tests are not valid for NSAIDs reactions, confirmation requires an appropriately-designed challenge. The latter could be avoided when the history is obvious and the reaction is life-threatening. The challenge route can be oral, nasal, or bronchial. Avoidance of the causative NSAID, often associated with the avoidance of the cross-reacting preparations, is the cornerstone of management. In most cases, a safe substitute can be used. When treatment with the causative NSAID is necessary, titrated desensitization can be performed. This review discusses the classes of NSAIDs, mechanisms of their adverse reactions, manifestations, diagnosis, and management.