Prospective appraisal of complaints of adverse reactions to foods in children during the first 3 years of life.

To examine the natural history of adverse reactions to foods, 480 children were followed prospectively from birth to their third birthdays. Foods thought to be causing symptoms were evaluated by elimination of suspected foods, open challenges, and double-blind food challenges. Foods producing symptoms were reintroduced into the diet at 1- to 3-month intervals until the symptoms no longer occurred. Of the 480 children completing the study, 28% were thought to have symptoms produced during food ingestion, but in only 8% were these reactions reproduced (excluding fruit and fruit juices). During the first year of life 80% of the initial complaints occurred. The most striking finding was the brief duration during which reactions could be reproduced. The majority of foods were replaced in the diet within 9 months of their incrimination. A long list of foods was reported to produce many symptoms, but only a few foods reproducibly evoked gastrointestinal and skin symptoms, with respiratory symptoms being infrequent. Of great interest was that 75 children were reported to react to fruit or fruit juice, and 56 of these children had reproducible symptoms. This study has found that most food reactions occur during the first year of life, but rechallenge at regular intervals has shown that the food can be reintroduced into the diet by the third year without risk. Almost all reactions that were reproduced appear to be non-immunoglobulin E mediated.