Prediction of Airway Hyperresponsiveness by Asthma Questionaire in Compare with Methacholine Challenge Test

Cho, Wan; Han, Man Yong

Abstract

PURPOSE
It is well-known that the bronchial challenge test is very important to evaluate the bronchial hyperresponsiveness in asthma. This study was done to find the items of clinical symptoms and signs as a predictors for bronchial hyperresponsiveness in compare with methacholine challenge test.
METHODS
The methacholine challenge test and allergy questionnaire(total 90 items) were done for 76 children with suspected asthma aged 4 to 11 years old who visited children's allergy clinic from the February to the June in 1999. Methacholine was used in increasing doses from 0.125 mg/mL to 16 mg/mL to a greater-than-20%(PC20) drop in FEV1 was obtained, or to the maximum concentration of 16 mg/mL was reached. The subjects were requested to inhale each preparation for 2 minutes. The bronchial hyperreactivity was considered severe if a PC20 was reached at a concentration of 0.125 mg/mL, moderate if the PC20 was reached at between 0.25 and 0.5 mg/mL(group C), mild if the PC20 was obtained with concentrations between 2 and 8 mg/mL(group B), and negative if the PC20 was obtained with concentrations 16 mg/mL or not obtained with any of the concentrations used(group A). We compared bronchial hyperreactivity with items of the questionnaire.
RESULTS
1) Fifteen children are normal(group A), thirty-nine are mild(group B), nineteen are moderate(group C), and three are severe(group C) among 76 children. 2) Symptom score and bronchial hyperreactivity showed statistical significant correlation. 3) Items which had statistical significance(P<0.05) between the methacholine challenge test and the questionnaire are dyspneic asthma attack, more than twice of asthma attck, asthma history diagnosed by doctor, wheezing regardless of common cold, and wheezing episode for last three months. 4) Family history, residential environment, duration of cough and other allergic disease history didn't have any relation.
CONCLUSION
Some items of asthma questionaire had a close relationship with the severity of bronchial hyperresponsiveness by methacholine challenge test for the children with suspected asthma. We hope that those items of asthma qyestionaire be helpful to predict the airway hyperresponsiveness for childhood asthma.