Phenotypic differences between asymptomatic airway hyperresponsiveness and remission of asthma

Summary Background The present study aimed to illustrate differences in characteristics and perception of dyspnea between young atopic adults who have no history of asthma ( never -asthmatics) with or without asymptomatic airway hyperresponsiveness (AHR) and those who had childhood asthma and consider themselves to be grown out of the disease ( past -asthmatics). Methods Blood parameters, lung function and methacholine PC20 were measured in 88 never -asthmatics and 24 past -asthmatics. A perception score of dyspnea at 20% fall in FEV1 (PS20 ) was obtained by interpolation of the two last points on the perception (modified Borg scale)/fall in FEV1 curve during methacholine challenge. Results Thirty-one of 88 never -asthmatics and eighteen of 24 past -asthmatics exhibited AHR (PC20 was