NIAID Releases First Guidelines for Managing Food Allergies

Emma Hitt, PhD

December 06, 2010

December 6, 2010 — The first food allergy guidelines were issued today by the National Institutes of Health's National Institute of Allergy and Infectious Diseases (NIAID).

According to the new guidelines, avoiding the ingestion of specific allergens is the main strategy suggested for managing food allergies, and no medications are currently recommended.

Developed over 2 years, the guidelines are intended for use by both family practice physicians and medical specialists and were published online today by the Journal of Allergy and Clinical Immunology. The full text of the guidelines are now available on the NIAID Web site.

Joshua A. Boyce, MD, from the Division of Rheumatology, Immunology and Allergy at Brigham and Women's Hospital in Boston, Massachusetts, chaired the 19-member panel of experts that devised the new guidelines. The NIAID also established a coordinating committee with members from 34 professional organizations, advocacy groups, and federal agencies.

"These guidelines are an important starting point toward a goal of a more cogent, evidence-based approach to the diagnosis and management of food allergy," Dr. Boyce said in an NIAID news release. "We believe that they provide healthcare professionals with a clear-cut definition of what constitutes a food allergy and a logical framework for the appropriate use of diagnostic testing and accurate interpretation of the results."

The guidelines, which include 43 clinical recommendations, discuss both IgE-mediated reactions to food and some non-IgE-mediated reactions. The panel defines food allergy as "an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food."

Food Allergies Increasing in US

The natural history of the most common food allergens in the United States — including egg, milk, peanut, tree nuts, wheat, crustacean shellfish, and soy — was reviewed and summarized. The incidence and prevalence of food allergies were found to have possibly changed over time, with many studies suggesting a true increase in prevalence over the last 10 to 20 years.

According to the literature summary in the new guidelines, most children with allergies to milk, egg, soy, and wheat will eventually be able to tolerate these allergens, while tree nut and peanut allergies are less likely to resolve with time. Likewise, food allergies that begin in adulthood are likely to persist.

The guidelines also note that food allergies tend to coexist with asthma, atopic dermatitis, eosinophilic esophagitis, and exercise-induced asthma. Eliminating food allergens can improve symptoms of some of these comorbid conditions.

Guidelines Recommend Confirmation of Allergies

The guidelines also describe conditions that should raise clinical suspicion of food allergies. In addition, they suggest that food allergies should be confirmed, because studies indicate that 50% to 90% of presumed food allergies are, in fact, not allergies.

The new guidelines will help physicians to know which tests have been scientifically evaluated to diagnose food allergy. Matthew Fenton, PhD, with the NIAID, explained at a press conference held Friday regarding the new guidelines.

"The guidelines have indicated what the strengths and weaknesses are of the different tests that can be used for the diagnosis," said Hugh Sampson, MD, with the Mount Sinai School of Medicine in New York City. After a patient history, skin and blood tests, "the oral food challenge is the only way to get to the answer," he added.

Vaccines in Egg-Allergic Populations

The guidelines also suggest that patients allergic to eggs should receive the measles, mumps, and rubella vaccine despite it being egg-based. Administering the egg-based yellow fever and rabies vaccines to these patients was not supported by a summary of the literature, and insufficient evidence was found to recommend the egg-based influenza vaccine for these patients.

"These vaccines can be quite safe in egg-allergic populations," Dr. Fenton said, "probably in part due to a continued lowering of the amount of contaminating egg protein in the vaccine, as manufacturing methods continue to improve over time."

The panel defines patients at risk for developing food allergies as "those with a biological parent or sibling with existing, or history of, allergic rhinitis, asthma, atopic dermatitis, or food allergy." However, these patients do not need to limit exposure to foods that may be cross-reactive with the most common food allergens.

Delaying of Foods Not Warranted

The guidelines do not recommend restricting maternal diet during pregnancy or lactation to prevent the development or clinical course of food allergies, but they do recommend exclusive breast-feeding of all infants until age 4 to 6 months, unless medical reasons contraindicate breast-feeding.

According to Dr. Sampson, the guidelines concur with current American Academy of Pediatrics guidelines. "There is no evidence that delaying certain foods, even foods that are considered allergenic, (is) going to have any significant effect on the development of allergy," he said.

Epinephrine the First Choice for Anaphylaxis

The recommended therapy for anaphylaxis is described in the guidelines. Dr. Sampson stressed that "epinephrine is the first choice for the treatment of anaphylaxis and many of the other drugs, such as antihistamines, corticosteroids, and such, are secondary medications."

"The food allergy guidelines provide a rigorous assessment of the state of the science, and clearly identify the areas where evidence is lacking and where research needs to be pursued," Daniel Rotrosen, MD, director of the Division of Allergy, Immunology and Transplantation at NIAID, said in the news release. "This information will help shape our research agenda for the near future."

Dr. Boyce serves on the advisory board of GlaxoSmithKline, has served as a consultant and/or speaker for Altana, GlaxoSmithKline, and Merck, and has received funding and grant support from the National Institutes of Health.

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