Bronchial challenge with aspirin lysine in the diagnosis of asthmatics with sensitization to aspirin and its inhibition by aerosolized furosemide.

We performed bronchial challenge with ASA lysine in 9 patients with a history of aspirin-induced asthma, 4 asthmatics with no history of hypersensitization to aspirin and 4 control subjects. The test consisted of successive inhalations of increasing concentrations of ASA lysine (11.25, 22.5, 45, 90, 180 and 360 mg/ml) and was interrupted when FEV1 showed a decrease of at least 20%. In order to determine the degree of bronchial hyperreactivity, we first carried out a bronchial challenge with histamine. All patients in the group sensitive to aspirin had a positive reaction to ASA lysine, while this was negative for patients in the two control groups. There was no significant correlation between PC20 to histamine and ASA lysine in any of the groups. On the other hand, 6 patients with sensitivity to ASA repeated the bronchial challenge with ASA lysine after previously inhaling furosemide, and in this second test, none of the 6 had a positive reaction. The variation of ASA lysine PC20 in both tests was positive for these patients (p < 0.001).