Bronchial hyperresponsiveness in children with atopic rhinitis: a 7-year follow-up.

BACKGROUND

A high prevalence of bronchial hyperresponsiveness (BHR) was found in atopic subjects with rhinitis. Those subjects may be at higher risk for developing bronchial asthma. We evaluated, in a 7-year follow-up, BHR and atopy in a homogeneous population of nonasthmatic children with allergic rhinitis (AR), and their role in asthma development.

METHODS

Twenty-eight children (6-15 years) with AR were studied. At enrollment (T(0)), skin tests, total serum IgE assay, peak expiratory flow (PEF) monitoring and methacholine (Mch) bronchial challenge were performed. BHR was computed as the Mch dose causing a 20% forced expiratory volume (FEV)(1) fall (PD(20)FEV(1)) and as dose-response slope (D(RS)). Subjects were reassessed after 7 years (T(1)) using the same criteria.

RESULTS

At T(0), 13 children (46%), showing a PD(20)FEV(1) <1526 microg of Mch, had BHR (Mch+), although PEF variability (PEFv) was within normal limits. None of the children with negative methacholine test developed bronchial asthma after 7 years. Of the 13 Mch+, only two reported asthma symptoms after 7 years. No significant change was seen in the other parameters of atopy considered.

CONCLUSION

Children with allergic rhinitis present a high prevalence of BHR. Nevertheless, their PEFv is normal and the rate of asthma development low.