New food allergy guidelines aid diagnosis, management

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

The complete guidelines were published online at the NIAID food allergy guidelines portal, along with a clinician summary and frequently asked questions. The guidelines establish consistent terminology and definitions, diagnostic criteria and patient management practices.

According to the guidelines, 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. The guidelines include a list of additional tests that should not be used for diagnosis.

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

Management of allergy patients should include avoidance of the food that causes the allergy, as well as 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. There are no medications recommended to prevent food allergies, but 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.

Treatment for food-induced anaphylaxis should be prompt and rapid, with intramuscular epinephrine as first-line therapy in all cases, and then adjunctive treatments such as bronchodilation, antihistamines and supplemental oxygen. Any patient treated for anaphylaxis should be discharged with:

• an anaphylaxis emergency action plan,two doses of an epinephrine auto-injector,a plan for monitoring auto-injector expiration dates,a referral for further evaluation by an allergist or immunologist andprinted information about anaphylaxis and its treatment.

Recent studies estimate that food allergy affects nearly 5% of children younger than 5 years old and 4% of teens and adults. Its prevalence appears to be on the rise, according to NIAID.