The development of acute respiratory tract reactions (upper and lower) to cyclooxygenase-1 (COX-1) inhibitors in the setting of asthma, chronic rhinosinusitis, and nasal polyposis is referred to aspirin-exacerbated respiratory disease (AERD). It is also known as nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD).

Exposure to COX-1 inhibitors does not initiate this inflammatory process but exacerbates it.

The clinical course develops over the course of years, beginning with rhinosinusitis, which becomes chronic and persistent, often with the development of nasal polyps. Patients subsequently develop asthma and then aspirin and other NSAID hypersensitivity.

The condition affects 0.6%-1.9% of the general population, though the prevalence is higher among diagnosed asthmatics and higher still (30%-40%) when patients with asthma, nasal polyposis, and chronic rhinosinusitis are assessed with aspirin provocation testing. The condition is never seen before puberty and is more prevalent in women than in men, with an average onset in the third decade of life.

Acute reactions to COX-1 inhibitors develop 30 minutes to 2 hours after exposure to the offending agent and are marked by bronchospasm, rhinorrhea, tearing, and in some cases skin rash. These reactions are based on dosage and the strength of the agent's COX-1 inhibition.