Atopy, bronchial hyperresponsiveness, and peak flow variability in children with mild occasional wheezing.

BACKGROUND

Children who suffer from recurrent wheezy episodes are often promptly classified as asthmatic. The aim of this study was to evaluate a population of mild wheezy children with repeatedly normal spirometric tests at rest for atopy, bronchial hyperresponsiveness, and peak expiratory flow variability.

METHODS

Thirty nine children aged 6-16 years with 1-12 wheezy attacks during the previous year were recruited from a community paediatric primary health care clinic serving an urban Israeli population. The conditions for inclusion were a physician-diagnosed wheeze on auscultation and normal spirometric tests at rest on at least three occasions. Evaluation included skin prick tests for atopy and a physician-completed questionnaire. In addition, two tests of bronchial hyperresponsiveness (BHR) were performed--namely, exercise-induced bronchospasm and inhaled methacholine hyperresponsiveness--as well as diurnal variability of peak expiratory flow (PV).

RESULTS

One or more tests of BHR/PV were positive in 27 (69%) but repeatedly negative in 12 (31%). In terms of frequency of wheezing attacks, atopy, and questionnaire responses, there were no differences between BHR/PV and non-BHR/PV children, with the exception of a history of chest radiography proven pneumonia (only noted in the BHR/PV group). Overall, evidence of atopy (mainly indoor allergens) was noted in 21 (56%) of those tested and parental smoking in 29 (74%) of households. Thirty-two (82%) of the children complained of an exercise-related wheeze, yet exercise-induced bronchospasm was only demonstrated in nine (23%).

CONCLUSIONS

This selected group of wheezy children appears to be intermediate between a normal and clearly asthmatic population and, despite the recurrent wheezy attacks, some should probably not be classified as asthmatic by conventional criteria. Important aetiological factors in the symptomatology of these children may include parental smoking and atopy as well as other elements such as viral infections.