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Persistence of Airway Obstruction and Hyperresponsiveness in Subjects With Asthma Remission: Discussion

Published in Asthma

Persistence of Airway Obstruction and Hyperresponsiveness in Subjects With Asthma Remission: DiscussionIn our study, asthma remission occurred between ages 11 and 20 years in most subjects but remissions were also observed after the age of 40 years. Remissions in asthmatic children have been well studied but little is known, however, of asthma remissions in adults. Spontaneous remissions of asthma have been reported to occur in 30 to 70 percent of subjects, mainly at adolescence. Martin et al also showed that children who had minor wheezing in childhood and were wheeze free for at least 3 years had normal pulmonary function, although 60 percent of these had an abnormal bronchial response to inhaled histamine more canadian neighbor pharmacy. Our results are in keeping with these observations as we observed the persistence of an increased response to methacholine in 63 percent of “ex-asthmatics.”
Radford et al compared the level of airway responsiveness between former and present asthmatic children. They reported that former asthmatics had persistence of airway hyperresponsiveness over time, compared with currently symptomatic asthmatics, but to a lesser degree. Gerritsen et al showed that 43 percent of 101 adults with asthma in childhood still had asthma symptoms, although the number of subjects with a PD10 histamine <16 mg/ ml went from 101 children to 29 adults. Of the 43 subjects with persistent symptoms, 59 percent had a positive response to histamine, compared with 7 percent of those without symptoms.
In an epidemiologic study on subjects over 70 years old, Burr et al reported that of 27 with a history of asthma, 7 reported a complete remission of their asthma and 5 reported some occasional “wheezing.” On the other hand, Bronnimann and Burrows evaluated 3,454 subjects from the general population after a follow-up of 9.4 years. Remissions of asthma were mainly observed in the second decade of life (65 percent of remissions) and were unfrequent between 30 and 60 years old (10 percent of remissions). Asthmatics with marked symptoms, reduced pulmonary function, or an associated diagnosis of chronic bronchitis or emphysema had lower remission rates. Our results are also in keeping with observations of Kaae Hansen et al who reported that apparently asymptomatic former asthmatics show signs of persistent airway hyperresponsiveness compared with controls.
During recruitment of controls, five subjects who considered themselves as normal and having no asthma symptoms on their initial questionnaire had airway hyperresponsiveness. Many studies have reported the presence of asymptomatic airway hyperresponsiveness. Cockcroft and Hargreave reported that 4.5 percent of normal asymptomatic adults and 12.7 percent of individuals with symptoms of rhinitis but not of asthma had airway hyperresponsiveness.