ABSTRACT
BACKGROUND: While aspirin sensitivity has been known to be common among patients with severe asthma, its frequency among asthmatics with mild to moderate severity remains to be learned. OBJECTIVES: To elucidate the frequency of aspirin sensitivity and its clinical characteristics among asthma patients with mild to moderate severity. MATERIAL AND METHODS: A total of 96 asthmatics with mild to moderate severity were enrolled. They underwent lysine-aspirin and methacholine bronchial provocation tests, and gave their induced sputum after the lysine-aspirin challenge. RESULTS: FEV1 declined greater than 20% compared with baseline FEV1 in 11 of 96 patients on the lysine-aspirin challenge. The frequency of aspirin sensitivity was higher among patients with enhanced bronchial hyperresponsiveness to methacholine (PC20 < 1 mg/ml) than among those without it (27.3% vs. 6.8%). The frequency was also higher in those with induced sputum eosinophil count higher than 3% than among those without it (38.9% vs. 0%). However, it was not associated with other risk factors such as age, sex, atopy, nasal polyps, and rhinosinusitis. CONCLUSION: More than 10% of mild to moderate asthmatics have aspirin sensitivity even though they have experienced no history of aspirin sensitivity which may be related with bronchial hyperresponsiveness to methacholine and eosinophil activation.