Allen CW, Kemp AS, Campbell DE. Pediatr Allergy Immunol. 2009;20(3):213–218
PURPOSE OF THE STUDY. To assess sources of dietary advice, adherence to advice, factors that influence adherence, and impact of dietary adherence on acquisition of tolerance among egg-allergic children.
STUDY POPULATION. One hundred sixty-seven children diagnosed with immunoglobulin E–mediated egg allergy and followed by a tertiary pediatric allergy center in Australia.
METHODS. In 2006, a questionnaire was mailed to parents of egg-allergic children who were seen in the clinic in 2003. The questionnaire included demographic data, initial and subsequent reaction history, and information on self-injectable epinephrine prescriptions. Reaction severity was categorized as grade 1 (localized erythema/urticaria), 2 (generalized erythema/urticaria, angioedema, and/or gastrointestinal symptoms), or 3 (generalized urticaria and stridor, wheeze, or cardiovascular compromise). The questionnaire also assessed the type and source of dietary advice given, dietary adherence, characteristics that affect adherence, and acquisition of tolerance to egg. Adherence to dietary advice was defined as following given advice “all of the time.” Oral tolerance to egg was based on the results of an oral food challenge (OFC).
RESULTS. The mean age of the study population was 6.6 years (mean follow-up period: 5.5 years). Coexisting atopic disorders were prevalent, with 83% of children having other food allergies and 56% having asthma. Only 21% reported having a prescription for self- injectable epinephrine, 47% reported accidental exposures, and 39% reported subsequent clinical reactions to egg. Sources of dietary advice included allergists (85%), dietitians (45%), and other health care providers (24%). Avoidance of all egg-containing products was recommended to 84%. A subset of the participants reported receiving conflicting advice; 39% reported that they were advised to avoid all egg traces, and 26% were advised that baked egg-containing foods were permitted. Of the 141 of 167 participants who were advised to avoid all egg products, 113 (80%) of 141 were adherent to dietary advice. Adherence rates were similar for other given dietary advice (avoiding trace egg or permitting baked egg). Adherence was not related to initial reaction severity or the source of advice (eg, doctors versus other sources). Eighty-four children underwent an egg OFC, and 27 (32%) of 84 passed. There were no statistically significant differences in demographic characteristics, initial reaction severity, accidental ingestion rates, advice given, or adherence patterns between those who passed versus failed the OFC.
CONCLUSIONS. Adherence to dietary advice was not related to patient characteristics, type or source of advice given, or initial reaction severity. Acquisition of oral tolerance was not related to strict adherence, accidental ingestions, or other patient characteristics such as reaction severity, type of dietary advice given, or atopic status.
REVIEWER COMMENTS. The results are perhaps surprising because neither exposures nor lack of exposures seemed to influence outcomes, although various confounding influences are difficult to assess. Measures of egg-specific immunoglobulin E were not reported; therefore, it is not clear whether serological markers would have better predicted outcomes. Other mechanisms, including antigen properties, serological markers, and host genetics, may aid in predicting oral tolerance acquisition. A better understanding of the natural history of oral tolerance acquisition would inform future therapies aimed at inducing oral tolerance, such as oral immunotherapy.
- Copyright © 2009 by the American Academy of Pediatrics