Published online Jul 28, 2016. doi: 10.5320/wjr.v6.i2.63
Peer-review started: November 23, 2015
First decision: December 28, 2015
Revised: February 2, 2016
Accepted: March 22, 2016
Article in press: March 23, 2016
Published online: July 28, 2016
Processing time: 243 Days and 12 Hours
Bronchial hyperresponsiveness (BHR) is an important but not asthma-specific characteristic and can be assessed by direct and indirect methods, based on the stimulus causing airway obstruction. BHR has been proposed as a prognostic marker of asthma severity and persistence, and may also be used to control pharmacological management of asthma. The most recent data on the prevalence and development of BHR in childhood and its predictive value for subsequent asthma development in late adolescence and adulthood is discussed in this review. According to the BHR-related scientific articles written in the English language and indexed in the publicly searchable PubMed database, the prevalence of BHR varies based upon the methods used to assess it and the population examined. In general, however, BHR prevalence is reduced as children grow older, in both healthy and asthmatic populations. While asthma can be predicted by BHR, the predictive value is limited. Reduced lung function, allergic sensitization, female sex, and early respiratory illness have been identified as risk factors for BHR. The collective studies further indicate that BHR is a dynamic feature related to asthma, but asymptomatic BHR is also common. Ultimately, the prevalence of BHR varies depending on the population, the environment, and the evaluation methods used. While both the methacholine challenge and the exercise test may predict asthma in adolescence or early adulthood, the predictive value is higher for the methacholine challenge compared to the exercise test. The collective data presented in the present study demonstrate how BHR develops through childhood and its relation to bronchial asthma.
Core tip: Bronchial hyperresponsiveness (BHR) is a dynamic feature related to asthma and is also common among children without an asthma diagnosis. In children, BHR may be predictive of asthma development. This review article summarizes the current literature on the prevalence of BHR, highlighting the reported evidence elucidating its risk factors and predictive value for asthma in children.