These patients are also often steroid dependent. However, this reaction may occur in any asthmatic patient, although it is rare in children. The cause of this reaction appears to be related to inhibition by aspirin of the enzyme cyclooxygenase. A large group of medications that also produce this inhibition, the nonsteroidal anti-inflammatory drugs (NSAIDs), may also cause the same asthmatic reaction. Characteristic Features of Aspirin-Sensitive Asthma The most common presentation is an adult patient who first develops severe nasal symptoms of congestion and drip. Sinusitis may also develop and nasal polyps are often discovered on examination. In these patients, bronchial asthma may not be present at first but tends to develop after the nasal problems. Once asthma surfaces, it is often severe and unstable. Several characteristics of aspirin-hypersensitivity asthma should be emphasized. Aspirin may produce an asthmatic attack even in patients who have previously taken it without any reaction. These attacks are usually severe, occurring within one hour of aspirin ingestion. The reaction may include flushing, nasal congestion, and eye irritation in addition to the asthmatic attack. Even a single aspirin tablet (or other anti-inflammatory agent that may cause bronchoconstriction) may produce a potentially fatal asthma attack. Once sensitivity to aspirin is established it does not resolve, and asthma patients should never again take this medication. How the Diagnosis Is Made The definitive diagnosis of aspirin-hypersensitivity asthma may only be made by documenting a reaction to this medication. A challenge test may be performed by experienced physicians with immediate access to medication to counter a severe reaction. Documentation may also be made through an accurate medical history. If so, the physician may not feel a challenge test is needed. Because of the danger of developing a severe asthma attack from aspirin ingestion, all asthma patients should avoid using aspirin.