title: Cough variant asthma: lessons learned from deep inspirations.
abstract: The pathophysiology of cough variant asthma is poorly understood. In particular, the mechanisms that cause different symptoms in typical asthma (in which wheeze predominates) compared with cough variant asthma (in which cough predominates) have not been determined. Traditional explanations include higher wheezing thresholds, differences in cough sensitivity, and/or differences in small airway function. Recent studies using high-dose methacholine challenge testing suggest that altered small-airway function plays a role. Preservation or loss of the bronchoprotective effect of a deep inspiration may be a fundamental pathophysiologic difference between asthma, cough variant asthma, methacholine-induced cough with normal sensitivity, and eosinophilic bronchitis.
authors.affiliation: Department of Medicine, Queen's University, 102 Stuart Street, Kingston, ON K7L 2V6, Canada. mdl@queensu.ca
authors.forename: M Diane
authors.initials: MD
authors.lastname: Lougheed
authors.forename: Scott E
authors.initials: SE
authors.lastname: Turcotte
authors.forename: Thomas
authors.initials: T
authors.lastname: Fisher
mesh_terms: D001249:Asthma / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000187:drug effects; D016085:Bronchoconstrictor Agents / Q000494:pharmacology; D003371:Cough / Q000209:etiology / Q000503:physiopathology*; D004804:Eosinophils; D006801:Humans; D007249:Inflammation / Q000150:complications / Q000503:physiopathology; D001239:Inhalation; D016210:Methacholine Chloride / Q000494:pharmacology
chemical_list: D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride