[Allergy and lung function in school children].

Abstract

In order to measure the effect of allergy on the lung function among schoolchildren a cross-sectional study has been performed in 1048 children of 10-11 year age who attended the grammar schools in Krakow. The lung function was assessed by the following spirometric indices: VC, FVC, FEV0.5, FEV0.75, FEV1, FEF25-75%, FEF0.2-1.2, PEFR while the data on allergy diagnosed clinically by physician was obtained by self-administered questionnaires from the parents of children. For those of the children who had the allergic skin test performed a search in medical records has been carried out. The frequency of allergy diagnosed clinically (without skin tests) was higher in boys (22.3%) than in girls (18.4%) and the same differences have been found for allergy confirmed by skin testing (15.7% vs. 9.3%). Except for VC and FVC, all adjusted mean values of spirometric indices were significantly lower in allergic than in non-allergic group of children. Regression coefficient of spirometric indices were related inversely with the presence of allergy. The greatest effects of allergy (without skin tests) have been observed on PEFR (-180 ml), FEF0.2-1.2 (-171 ml), FEF25-75% (-121 ml) and for FEV0.75 (-69 ml) and FEV1 (-68 ml). The smallest differences were found for VC and FVC. The additional series of analysis done in the subgroup of children without attacks of dyspnea with wheezing or wheezing independent from colds or respiratory infections confirmed the results obtained in the total study sample. The prevalence of obstructive syndrome, defined as FEV1/FVC < 80%, was 4.5% in the total sample, however, only 2.9% in non-allergic children, 7.2% in children in whom allergy was diagnosed by physicians and 8.5% among those children among whom allergy was diagnosed by allergic skin tests.