Atopic dermatitis and concomitant disease patterns in children up to two years of age.

There are few prospective studies of atopic dermatitis and co-existing diseases such as respiratory infections in children up to 2 years of age. Using annual questionnaires, we studied the cumulative incidence of atopic dermatitis and concomitant symptoms indicating other atopic diseases and respiratory infections in 0-2-year-old children in a prospective birth cohort of 4089 children. We found associations between atopic dermatitis and asthma (ratio of proportion 1.45, 95% CI 1.16-1.80), allergic rhinoconjunctivitis (RP 2.25, CI 1.77-2.85), adverse reactions to foods (RP 3.20, CI 2.83-3.62), urticaria (RP 2.04, CI 1.80-2.31), acute otitis media (RP 1.13, CI 1.05-1.21), more than one pneumonia during the first and/or second year of life (RP 2.17, CI 1.14-4.15), and use of antibiotics at least twice yearly (RP 1.29, CI 1.07-1.56). The association between atopic dermatitis and respiratory infections persisted after stratification for asthma. There was a higher proportion of atopic disease manifestations, but not respiratory infections, in children with onset of atopic dermatitis during the first year of life than during the second. The study shows that during the first 2 years of life there is a significant association not only between atopic dermatitis and other atopic disease manifestations, but also between atopic dermatitis and respiratory infections manifested in an increased rate of acute otitis media, pneumonia and use of antibiotics.