Young children with allergies to milk and egg experience reactions to these and other foods more often than researchers had expected, a study reports. The study also found that severe and potentially life-threatening reactions in a significant number of these children occur and that some caregivers are hesitant to give such children epinephrine, a medication that reverses the symptoms of such reactions and can save lives.
"This study reinforces the importance of doctors, parents and other caregivers working together to be even more vigilant in managing food allergy in children," said Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
The study results appear online in the June 25 issue of Pediatrics and are the latest findings from the Consortium of Food Allergy Research (CoFAR), a network established by NIAID to conduct clinical trials, observational studies and basic research to better understand and treat food allergy.
The research is part of an ongoing CoFAR observational study that enrolled 512 infants aged 3 to 15 months who at study entry were allergic to milk or egg, or who were likely to be allergic, based on a positive skin test and the presence of moderate-to-severe eczema, a chronic skin condition. The investigators are carefully following these children to see whether their allergies resolve or if new allergies, particularly peanut allergy, develop. The study is ongoing at research hospitals in Baltimore; Denver; Durham, N.C.; Little Rock, Ark.; and New York City.
CoFAR investigators advised parents and caregivers to avoid giving their children foods that could cause an allergic reaction. Study participants also received an emergency action plan, describing the symptoms of a severe allergic reaction to food and what to do if a child has one, along with a prescription and instructions on how to give epinephrine if a severe reaction occurred.
Data compiled from patient questionnaires and clinic visits over three years showed that 72 percent of the children had a food-allergic reaction, and that 53 percent of the children had more than one reaction, with the majority of reactions being to milk, egg or peanut. This translated into a rate of nearly 1 food-allergic reaction per child per year. Approximately 11 percent of the reactions were classified as severe and included symptoms such as swelling in the throat, difficulty breathing, a sudden drop in blood pressure, dizziness or fainting. Almost all of the severe reactions were caused by ingestion of the allergen rather than inhalation or skin contact.
In only 30 percent of the severe reactions did caregivers administer epinephrine, a drug that alleviates the symptoms of severe reactions by increasing heart rate, constricting blood vessels and opening the airways. Investigators found that caregivers did not give children epinephrine for a number of reasons: the drug was not available, they were too afraid to administer it, they did not recognize the symptoms as those of an allergic reaction, or they did not recognize the reaction as severe.
"This study documenting the natural history of allergic reactions to three of the major food allergens in pre-school children provides important new information for parents, caregivers and health care workers because of the large number of children involved and the rigorous follow-up," said Daniel Rotrosen, M.D., director of the NIAID Division of Allergy, Immunology and Transplantation, which oversees CoFAR. "The findings not only reveal that food-allergic reactions occur at a much higher rate in young children than we thought, they also suggest that more vigilance and increased use of epinephrine is needed."
Almost 90 percent of allergic reactions to egg, milk or peanut occurred after a child accidentally ate the food. The reasons for the accidental exposures included caregivers misreading food labels, not checking a food for an allergen, and unintentionally allowing a food allergen to come into contact with other foods (cross-contamination).
The study also found that approximately 11 percent of allergic reactions to egg, milk or peanut occurred after a caregiver—most often a parent—provided a child the allergenic food intentionally.
"Intentional exposures to allergenic food are typically reported in teenagers, who tend to take more risks or who might be embarrassed about their food allergy," says David Fleischer, M.D., the lead study author. "What is troubling is that in this study we found that a significant number of young children received allergenic foods from parents who were aware of the allergy."
CoFAR investigators are exploring possible reasons for these intentional exposures, but they speculate that it could reflect parents' at-home tests to determine if children have outgrown the food allergy. Because giving children allergenic foods could possibly result in life-threatening reactions, such testing should only be conducted under the direct supervision of a health care professional trained in performing food challenges. The study findings reinforce the importance of caregivers working closely with their doctors to understand how to effectively manage a child's food allergy.
This work was funded by NIH, NIAID under grant numbers U19AI066738 and U01AI066560, and the National Center for Research Resources and the National Center for Advancing Translational Sciences, NIH, under grant numbers UL1RR025780, UL1RR029887, UL1RR029884, UL1RR024128 and UL1RR025005. The clinicaltrials.gov identifier for An Observational Study of Childhood Food Allergy is NCT00356174.
Parents and caregivers are encouraged to view the patient-friendly synopsis of the U.S. food allergy guidelines, which summarizes the most important information from the guidelines published on Dec. 6, 2010 and provides a starting point for doctor-patient conversations about food allergy. For additional free resources, visit NIAID's Food Allergy Web portal.
NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website at http://www.niaid.nih.gov.
About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.
Reference: Fleischer DM et al. Allergic reactions to foods in preschool children enrolled in a prospective observational food allergy study. Pediatrics. DOI: 10.1542/peds.2011-1746 (2012).
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