Bronchial hyperresponsiveness and asthma in the paediatric population

Abstract

Objective: To determine whether the intensity of bronchial hyperresponsiveness (BHR) is correlated to other clinical data such as patient age at the onset of asthma, the serum IgE levels and familial genetic susceptibility, with the purpose of establishing a prognosis or phenotype.

Material and methods: BHR was evaluated using the methacholine provocation test, with the patients divided into six groups according to the amount of methacholine needed to obtain PD20. A total of 138 children and adolescents up to age 18 years (94 males and 44 females) were included. Most had a clinical diagnosis of asthma, while tracheobronchitis or rhinitis was diagnosed among the least reactive subjects. The patients were divided into subjects with a family history of atopic disease (84 cases) and those without such a history (54 cases). In this latter case we discuss possible causes of BHR or dyspnoea triggering factors.

Results: There were no significant differences in patient age at onset or in serum IgE among the patients with different intensities of BHR, or between those with a family history of atopic disease and those without.

Conclusions: No differences were found among the groups. It is therefore concluded that the intensity of BHR is not a valid parameter for establishing a prognosis or phenotype, although it can be used to assess the severity of asthma.

Keywords: Adolescents; Asthma; Atopy; Bronchial hyperresponsiveness; Children; Genetics; Rhinitis; Tracheobronchitis.