Atopy in subjects with asthma followed to the age of 28 years.

The relationship between markers of asthma and atopy was examined in 323 subjects at the age of 28 years who have been followed since the age of 7 years. Hay fever was common in all groups with severe asthma, increasing from 25% of the control group to 67% of the group with the most severe asthma, class V. Eczema was uncommon at this age in all groups. IgE levels, peripheral blood eosinophil counts, and skin reactions were significantly (p less than 0.05) higher in class V than in the control group. Increasing age was associated with a progressive fall in eosinophil counts and an increase in skin reactivity to common allergens. No change in IgE levels was observed from 21 to 28 years. A general relationship between bronchial hyperreactivity and atopic markers was found. However, only the occurrence of hay fever was significantly related to reactivity when account was taken of severity of asthma. The results indicate that the relationship between asthma and atopy observed at earlier reviews continues into adult life and that bronchial hyperreactivity and atopy are not directly linked.