Interpretation of Positive Results of a Methacholine Inhalation Challenge and 1 Week of Inhaled Bronchodilator Use in Diagnosing and Treating Cough-Variant Asthma

Abstract

No matter how the results are analyzed, positive MIC results, without observing response to therapy, are only consistent with asthma as the cause of the cough. The results are only diagnostic of asthma when they are followed by a favorable response to asthma therapy. After 1 week of inhaled beta-agonist, only the cough due to cough-variant asthma is significantly better.