Aspririn and nonsteroidal anti-inflammatory drug hypersensitivity

Acetylsalicylic acid (ASA) or aspirin and nonsteroidal anti-inflammatory drug (NSAID) sensitivities encompass a diverse group of both pharmacological and hypersensitivity reactions. Conventionally, hypersensitivities include aspirin-exacerbated respiratory disease (AERD), ASA-induced urticaria, and anaphylaxis. With an increasing prevalence of coronary artery disease in an aging population, aspirin continues to play a significant role in cardiac prophylaxis in a large patient population. Invariably, the clinician will encounter patients with clear indications for aspirin therapy but a history of aspirin sensitivity. Although protocols have been established for aspirin challenge and desensitization, it is not always an efficacious or safe procedure. This article reviews the different classifications of ASA/NSAIDs hypersensitivities to better guide the clinician in dealing with this patient population. History of crossrelativities between multiple NSAIDs implies a non-IgE-mediated process. Similarly, a history of monosensitivity to one NSAID implies an IgE-mediated process, although specific antibodies are often elusive. Despite the name, AERD can potentially be exacerbated by all cyclooxygenase (COX) inhibitors based on dose-dependent inhibition of COX-1. Aspirin desensitization can be achieved to improve both upper and lower respiratory symptoms for most patient with AERD. Aspirin desensitization can usually be achieved for those in need of the antiplatelet effects of aspirin, with the exception of those with aspirin-induced urticaria and baseline chronic urticaria.