Association between severity of atopic eczema and degree of sensitization to aeroallergens in schoolchildren

Background: A subgroup of patients with atopic eczema exhibits aggravation through contact with aeroallergens. Little is known from population-based s tudies, however, about the association between the severity of eczematous s kin disease and the degree of aeroallergen sensitization. Objective: We sought to investigate the relationship between IgE-mediated a llergic sensitization to aeroallergens and severity of atopic eczema in sch oolchildren. Methods: A nested case-control analysis on atopic eczema was performed on t he basis of a cross-sectional study of 2201 Last German schoolchildren aged 5 to 14 years. Atopic eczema and its severity was identified by dermatolog ic examination. Total and allergen-specific IgE antibodies to grass and bir ch pollen, Cladosporium herbarum, Dermatophagoides pteronyssinus, and cat e pithelium in serum were determined, and additional information was obtained by means of standardized questionnaire. Results: The overall prevalence of actual atopic eczema was 2.5%. Thirty-se ven percent of the children were sensitized to at least one allergen. Child ren with atopic enema were significantly more often sensitized than those w ithout skin disease (75.0% vs 36.3%; odds ratio. 5.27; 95% confidence inter val, 2.54-11.15). This was observed for each single allergen. The prevalenc e of atopic eczema increased significantly with increasing RAST class (chi( 2) trend test for each allergen, P < .0001). Also, the prevalence of sensit ization increased with the severity of the disease (chi(2) trend test for e ach allergen, P < .0001). This association was pronounced for house dust mi te and cat allergen. Multiple linear regression analyses showed significant associations between the severity score of atopic eczema and concentration s of allergen-specific IgE to dust mite (P = .032) and cat (P = .014) aller gens after adjustment for ses, age, location, and parental predisposition. Conclusions: The degree of sensitization is directly associated with the se verity of atopic eczema. We speculate that earl epicutaneous sensitization to aeroallergens may be enhanced by damage of the skin barrier function. Th e specific IgE response seems to contribute to the severity of the disease in a dose dependent fashion.