Bronchoprovocation test in the normal and in asthmatics
Tsai, J.J.; Shih, J.T.; Lee, H.L.; Wang, S.R.
Zhonghua Minguo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 19(2): 118-123
1986
ISSN/ISBN: 0253-2662 PMID: 3545701 Document Number: 284406
The bronchoprovocation test has been widely used in diagnosis of bronchial asthma. Forty-eight cases under tentative diagnosis of bronchial asthma, with complaints of cough, shortness of breath, and wheezing, were studied by using histamine and methacholine. Their baseline pulmonary functions were all normal. Among the fourteen cases, histamine and methacholine provocation tests were both negative in 14 cases (29%) (Group 1). There were 18 cases (37%) of allergic asthmatics with positive challenge to either histamine (2 cases) of methacholine (1 case) or both (15 cases) (Group 2). There were 16 cases (34%) of nonallergic asthmatics with positive challenge to either histamine (2 cases) or methacholine (3 cases) or both (11 cases) (Group 3). In Group 2, the average PD20 FEV1 for methacholine and histamine was 25.8 .+-. 8.2 BU and 22.9 .+-. 7.1 BU respectively; the average PD25 FEF25-75 for methacholine and histamine was 19.4 .+-. 7.0 BU and 21.1 .+-. 7.1 BU respectively. The sensitivities, compared between both agents, were nearly the same. In Group 3, the average PD20 FEV1 for methacholine and histamine was 35.1 .+-. 9.0 BU and 54.5 .+-. 9.6 BU respectively; the average PD25 FEF25-75 for methacholine and histamine was 27.9 .+-. 8.6 BU and 50.2 .+-. 9.6 BU respectively. Methacholine is more sensitive in detecting airway hyperreactivity in this group. When these two groups of asthmatics were compared, Group 2 patients were more sensitive to challenges with histamine and methacholine (p < 0.02). In conclusion, bronchial challenge is useful in diagnosis of bronchial asthma and probably in avoiding the misdiagnosis of bronchial asthma. Patients more allergic in nature are more sensitive to the provocation test. Methacholine is more sensitive than histamine in the diagnosis of non-allergic asthmatics.