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 ris k 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 t he 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 perf ormed, 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, s ymptoms 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 developin g asthma was higher in children with a heredity of eczema. Presence of seve re eczema at the time of inclusion in the study was associated with an incr eased tendency to produce food-specific IgE. An early onset of eczema was a ssociated with an increased risk of sensitization to inhalant allergens, an d development of urticaria. Early allergic reactions to food were associate d with later reactions to food, allergic rhinitis, urticaria, and sensitiza tion to both food and inhalant allergens. Early feeding patterns, time of w eaning, and introduction of solid food did not influence the risk of develo pment of allergic symptoms. A large number of periods or days with fever du ring the follow-up was associated with an increased risk of developing alle rgic 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 followi ng factors: a family history of eczema, age at onset of eczema and its seve rity, early adverse reactions to foods, and proneness to infections.