Follow-up of children with rhinitis and cough associated with milk allergy.

Young children sensitized with foods may develop early respiratory symptoms including nasal symptoms and cough, but not clinical manifestations in the skin or gastrointestinal tract. The long-term outcome of these patients is largely unknown. We studied 36 children sensitized with cow's milk and three different age-matched control groups. The patients were followed from 12 to 18 months of age for at least 5 yr with repeat skin testing and oral food challenge. After 2(1/2) yr, 63.9% (n = 23) of those in the mild allergy group lost sensitivity to foods; after 5 yr, the number was 86.1% (n = 31). However, during the study period of 5 yr, 69.4% (n = 25) simultaneously developed a sensitivity to common indoor airborne allergens. A similar trend was found only in the egg allergy control group. A positive family history and a history of parental smoking significantly increased the relative risk (RR) of sustaining nasal allergy symptoms (RR = 3.33 and 1.79, respectively). We concluded that allergy march from food sensitivity to sensitivity to airborne allergens may occur in a subset of children before 4 yr of age. Genetics and environmental factors might independently contribute to the continuation of these respiratory symptoms.