New Food Allergy Guidelines

The National Institute of Allergy and Infectious Diseases (NIAID) issued comprehensive food allergy guidelines to help primary care physicians and subspecialists diagnose and manage patients.

The guidelines were published online at the NIAID food allergy guidelines portal, which also has a frequently asked questions section. The agency will release a patient synopsis early next year.

The guidelines establish consistent terminology and definitions, diagnostic criteria and patient management practices. Additional topics covered by the guidelines include the prevalence of food allergy and management of acute allergic reactions to food, including anaphylaxis. The report also identifies gaps about what is known about food allergy.

NIAID Director Anthony S. Fauci, MACP, said, “Because these guidelines provide standardized, concise recommendations on how to diagnose and manage food allergy and treat acute food allergy reactions across specialties, we expect both clinicians and food allergy patients to greatly benefit from these clear state-of-the-science clinical standards.”

The guidelines define food allergies and food intolerances, breaks down why prevalence has been so hard to establish, looks at co-morbid conditions such as asthma, and breaks down how clinicians should diagnose food allergies.

In brief, food allergies should be considered in those presenting with anaphylaxis or any combination of other symptoms that occur within minutes to hours of ingesting food, especially in young children and/or if symptoms have followed the ingestion of a specific food on more than one occasion. Following a detailed history and physical, a skin prick test may help identify foods at issue, although it alone is not considered diagnostic.

Intradermal tests and routine total serum IgE should not be used, and the atopy patch test should not be used in noncontact food allergies. However, food elimination diets may be useful in diagnosis, and double-blind, placebo-controlled food challenges are a gold standard.

These tests should not be used to diagnose IgE-mediated food allergies:

–basophil histamine release/activation,

–lymphocyte stimulation,

–facial thermography,

–gastric juice analysis,

–endoscopic allergen provocation,

–hair analysis,

–applied kinesiology,

–provocation neutralization,

–allergen-specific IgG4

–cytotoxicity assays,

–electrodermal test (Vega), and

–mediator release assay (LEAP diet)

Management stresses avoiding the food that causes the allergy, but also stresses education, careful attention to food labels and regular growth checks. The panel did not recommend avoiding potentially allergenic foods as a means of managing eosinophilic esophagitis, food protein-induced allergic proctocolitis, or asthma.

Follow-up intervals depend upon the patient’s history, allergy, and age.

There are no medications recommended to prevent food allergies. Antihistamines may be used to manage symptoms. Drug therapies have been used when the allergen is difficult to avoid or results in nutritional deficiencies.

The panel does not recommend restricting maternal diet during pregnancy or lactation to prevent later food allergies. Also, all infants should be exclusively breast-fed until four to six months, unless medical reasons contraindicate, and soy infant formula instead of cow’s milk infant formula should not be used to try and prevent allergies in “at-risk” infants, such as those with siblings with allergies. Hydrolyzed infant formulas, as opposed to cow’s milk formula, may be considered for preventing the development of food allergies in at-risk infants who are not exclusively breast-fed, while considering cost and availability. Solid foods should not be delayed beyond 4 to 6 months of age. Potentially allergenic foods may be introduced at this time as well.

Treatment for food-induced anaphylaxis should focus on prompt and rapid treatment, intramuscular epinephrine as first-line therapy in all cases, and then adjunctive treatments such as bronchodilation, antihistamines and supplemental oxygen.

Food allergy has become a serious health concern in the United States. Recent studies estimate that food allergy affects nearly 5 percent of children younger than 5 years old and 4 percent??of teens and adults. Its prevalence appears to be on the rise, according to NIAID.