Relationship between asthma and seasonal allergic rhinitis in schoolchildren.

The relationship between sensitization to common allergens and the development of asthma and seasonal allergic rhinitis (SAR) was investigated in a total of 419 schoolchildren in a farming community where allergens of both Dermatophagoides farinae (Df) and orchard grass (OG) pollen predominate. Twelve subjects (2.9%) were found to have asthma and 35 subjects (8.4%) SAR. There was no significant association between occurrences of asthma and SAR. The incidence of asthma correlated with DF-specific IgE levels but not with OG-specific IgE levels, whereas that of SAR correlated with OG-specific IgE levels but not with Df-specific IgE levels. No significant correlation was detected between IgE antibody levels against Df and OG. These results suggest that asthma occurs independently of SAR.