Development of allergies and asthma in infants and young children with atopic dermatitis--a prospective follow-up to 7 years of age.

BACKGROUND: The prognosis of atopic dermatitis is usually good, but the risk of developing asthma and allergic rhinitis is very high. The aim of this study was to follow children with atopic eczema up to school age to chart the course of sensitization and development of clinical allergy, as well as to study risk factors of sensitization.

METHODS: Ninety-four children with atopic dermatitis were followed up to 7 years of age. The children were examined twice a year up to 3 years of age, and thereafter once yearly. At each visit, a clinical examination was performed, and a blood sample was taken. After 3 years of age, skin prick tests (SPTs) with inhalation allergens were performed at each visit. Information was obtained about atopy in the family, feeding patterns during infancy, symptoms of atopic disease, infections, and environmental factors.

RESULTS: During the follow-up, the eczema improved in 82 of the 94 children, but 43% developed asthma and 45% allergic rhinitis. The risk of developing asthma was higher in children with a heredity of eczema. Presence of severe eczema at the time of inclusion in the study was associated with an increased tendency to produce food-specific IgE. An early onset of eczema was associated with an increased risk of sensitization to inhalant allergens, and development of urticaria. Early allergic reactions to food were associated with later reactions to food, allergic rhinitis, urticaria, and sensitization to both food and inhalant allergens. Early feeding patterns, time of weaning, and introduction of solid food did not influence the risk of development of allergic symptoms. A large number of periods or days with fever during the follow-up was associated with an increased risk of developing allergic rhinitis and urticaria.

CONCLUSIONS: Our results confirm the good prognosis for the dermatitis and the increased risk of developing asthma and allergic rhinitis. Development of other allergic symptoms or sensitization was associated with the following factors: a family history of eczema, age at onset of eczema and its severity, early adverse reactions to foods, and proneness to infections.