To investigate the frequency, characteristics, and risk factors of community-based adverse food reactions, including anaphylaxis, among children with food allergies at 6 years of age in a population-based cohort: the HealthNuts study.

The HealthNuts study is a longitudinal population-based study of childhood allergic disease in Melbourne, Australia in which researchers originally enrolled 5276 12-month old infants from community immunization clinics. In this report, 3233 children from this cohort are involved who, at 6 years of age, returned for an assessment. An additional 1222 only completed a questionnaire.

All caregivers completed questionnaires, and children underwent skin-prick tests to milk, egg, peanut, soy, wheat, sesame, shellfish, cashew, almond, hazelnut and a panel of aeroallergens. Oral food challenges (OFCs) were performed for eligible children. Children were identified as definite or probable food allergy on the basis of skin tests and/or a history of food reactions or results of OFCs. A total of 413 children were eligible for an OFC.

A total of 260 children were confirmed as having a food allergy. A total of 44.6% reported an adverse food reaction in the previous 12 months, nearly one-third having >1, with 73% likely immunoglobulin E–mediated. The most common symptoms were hives and vomiting. The most common foods were nuts and egg. One-half of the reactions occurred at home, with restaurants second (11.6%). A total of 28 children reported anaphylactic reactions; nearly one-half were not recognized as such by parents. Tree nuts (mostly cashew) and peanuts accounted for 65% of the anaphylactic reactions. Epinephrine autoinjectors were used in only 13.8% of all anaphylaxis episodes, only 25% of the parent-recognized anaphylaxis episodes, and none of the unrecognized anaphylaxis episodes. There were no risk factors identified for experiencing an adverse food reaction or anaphylaxis, but children with nut allergies were less likely to report an adverse food reaction compared with those without a nut allergy.

A high-frequency of adverse food reactions and anaphylaxis in food-allergic children at the age of 6 years occurred in this population-based cohort study. Only one-half of the episodes of anaphylaxis were identified as such, and only 25% of those were treated with an Epinephrine autoinjector. Improved regular education on the prevention of adverse food reactions and recognition and management of anaphylaxis is needed.

Pediatricians and other primary care practitioners need to review avoidance measures, possible symptoms or signs of anaphylaxis, and the importance of epinephrine as first-line therapy for anaphylaxis as part of their well-child care for patients with food allergies.