Last updated September 2, 2022

Food Allergy

Diagnosis

The general population of children need not be tested for FA to highly allergenic foods prior to their introduction into the diet. ( B , III )

Note: The general population of children does not have pre-existing severe allergic disease and also does not have a family history of FA.

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The health care professional considering a diagnosis of food-induced anaphylaxis should understand: ( A , III )
  • The signs and symptoms characteristic of anaphylaxis
  • The timing of symptoms in association with food ingestion/exposure
  • Comorbid conditions, such as asthma, that may affect treatment and outcome
  • The limited utility of laboratory parameters in the acute care setting
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FA should be considered: (A, II)
  • In individuals presenting with anaphylaxis or any combination of symptoms listed in Table 1 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
  • In infants, young children and selected older children diagnosed with certain disorders, such as moderate to severe AD, EoE, enterocolitis, enteropathy, and AP
  • In adults diagnosed with EoE
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Use the medical history and physical examination to aid in the diagnosis of FA. (A, III)
  • Medical history: The expert panel (EP) recommends using a detailed medical history to help focus the evaluation of an FA. Although the medical history often provides evidence for the type of food-induced allergic reaction and the potential causative food(s) involved, history alone cannot be considered diagnostic of FA.
  • Physical examination: The EP recommends performing a focused physical examination of the patient, which may provide signs consistent with an allergic reaction or disorder often associated with FA. However, by itself, the physical examination cannot be considered diagnostic of FA.
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Parent and patient reports of FA must be confirmed, because multiple studies demonstrate that 50% to 90% of presumed FAs are not allergies. (A, I)
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A skin puncture test (SPT) ( A , II )
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Allergen-specific IgE (sIgE) tests ( A , II )
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But NOT intradermal testing ( A , III )
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And NOT the routine use of measuring total serum IgE ( A , III )
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Do NOT use atopy patch test (APT) for the routine evaluation of noncontact FA. ( B , III )
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Eliminating one or a few specific foods from the diet may be useful in the diagnosis of FA, especially in identifying foods responsible for some non-IgE-mediated food-induced allergic disorders, such as FPIES, AP, and Heiner syndrome, and some mixed IgE- and non-IgE-mediated food-induced allergic disorders, such as EoE. ( B , III )
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Use oral food challenges for diagnosing FA. ( A , I )
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Note: The double-blind, placebo-controlled food challenge is the gold standard. However, a single-blind or an open-food challenge may be considered diagnostic under certain circumstances: if either of these challenges elicits no symptoms (ie, the challenge is negative), then FA can be ruled out; but when either challenge elicits objective symptoms (ie, the challenge is positive) and those objective symptoms correlate with medical history and are supported by laboratory tests, then a diagnosis of FA is supported.


Do NOT use any of the following nonstandardized tests for the routine evaluation of IgE-mediated FA:
  • 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)
  • Mediator release assay (Lifestyle Eating and Performance [LEAP] diet
( A , III )
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SPTs, slgE tests, and APTs may be considered to help identify foods that are associated with EoE, but these tests alone are not sufficient to make the diagnosis of FA. ( B , III )
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Note: The role of these tests in the diagnosis of other eosinophilic GI diseases has not been established.

Use the medical history and oral food challenge to establish a diagnosis of FPIES. ( A , I )
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Note: However, when history indicates that infants or children have experienced hypotensive episodes or multiple reactions to the same food, a diagnosis may be based on a convincing history and absence of symptoms when the causative food is eliminated from the diet.

Use the medical history, resolution of symptoms when the causative food is eliminated from the diet, and recurrence of symptoms following an oral food challenge to diagnose AP. ( A , II )
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Use the medical history, including the absence of symptoms while the causative food is avoided, and positive patch tests to diagnose ACD. ( A , II )
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Use the medical history, including the resolution of symptoms while the causative food is avoided, and positive patch tests to establish the diagnosis of systemic contact dermatitis. ( B , III )
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Use the medical history, including the absence of symptoms while the causative food is avoided, positive sIgE tests or SPTs, and positive immediate epicutaneous skin tests (for example, positive immediate responses to APTs), to establish the diagnosis of food-induced IgE-mediated contact urticaria. ( B , III )
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Consider children less than 5 years old with moderate to severe AD for FA evaluation for milk, egg, peanut, wheat, soy, and any other food that the parents reported to trigger atopic dermatitis, if at least one of the following conditions is met:
  • The child has persistent AD in spite of optimized management and topical therapy.
  • The child has a reliable history of an immediate reaction after ingestion of a specific food.
( B , III )
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Follow Up

Use follow-up testing for individuals with FA depending on the specific food to which the individual is allergic. Whether testing is done annually or at other intervals depends on the food in question, the age of the child, and the intervening medical history. ( B , II )
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Prevention

Patients at risk* for developing FA do not need to limit exposure to foods that may be cross-reactive with the 8 major food allergens in the United States (milk, egg, peanut, tree nuts, soy, wheat, fish, and crustacean shellfish) or to potential nonfood allergens (for example, dust mites, pollen, or pet dander). ( B , III )
* Patients at risk for developing FA are defined as those with a biological parent or sibling with existing, or history of, allergic rhinitis, asthma, AD, or FA.
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Individuals with documented or proven IgE-mediated or non-IgE-mediated FA should avoid ingesting their specific allergen or allergens. (A, III)
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Patients with FA and their caregivers should be provided with information on food allergen avoidance and emergency management that is age and culturally appropriate. ( A , III )
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Individuals without documented or proven FA need not avoid potentially allergenic foods as a means of managing AD, asthma, or EoE. (A, II)
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All children with FA should have nutritional counseling and regular growth monitoring. ( A , III )
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Individuals with FA and their caregivers should receive education and training on how to interpret ingredient lists on food labels and how to recognize labeling of the food allergens used as ingredients in foods. Products with precautionary labeling, such as ‘‘this product may contain trace amounts of [allergen]’’ should be avoided. ( B , III )
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There are no medications currently recommended to prevent IgE-mediated or non-IgE-mediated food-induced allergic reactions from occurring in an individual with existing FA. ( A , II )
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Immunizations

Although consensus recommendations for MMRV vaccine vary from the different organizations, children with egg allergy, even those with a history of severe reactions, should receive vaccines for measles, mumps, and rubella (MMR) and for MMR with varicella (MMRV). ( A , III )
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Note: The safety of this practice has been recognized by ACIP and AAP and is noted in the approved product prescribing information for these vaccines.

Pregnancy and Infancy

Restricting maternal diet during pregnancy or lactation as a strategy for preventing the development or clinical course of FA is NOT recommended. ( A , III )
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All infants should be exclusively breast-fed until 4 to 6 months of age, unless breastfeeding is contraindicated for medical reasons. ( A , III )
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Using soy infant formula instead of cow’s milk infant formula is NOT recommended as a strategy for preventing the development of FA or modifying its clinical course in at-risk* infants. ( A , II )
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Consider using hydrolyzed infant formulas, as opposed to cow’s milk formula, as a strategy for preventing the development of FA in at-risk* infants who are not exclusively breast-fed. ( B , II )
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Note: Cost and availability of extensively hydrolyzed infant formulas may be weighed as prohibitive factors.

The introduction of solid foods should NOT be delayed beyond 4 to 6 months of age. Potentially allergenic foods may be introduced at this time as well. ( B , III )
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* Patients at risk for developing FA are defined as those with a biological parent or sibling with existing, or history of, allergic rhinitis, asthma, AD, or FA.

Treatment Summary

The management of food-induced anaphylaxis should focus on the following:
  • Dosing with IM epinephrine followed by transfer to an emergency facility for observation and possible further treatment
  • Observation for 4-6 hours or longer based on severity of the reaction
  • Education for patient and family on:
    • Allergen avoidance
    • Early recognition of signs and symptoms of anaphylaxis
    • Anaphylaxis emergency action plan implementation
    • Appropriate IM epinephrine administration
    • Medical identification jewelry or an anaphylaxis wallet card
  • Epinephrine auto-injector prescription and training provided at the time of discharge
  • Continuation of adjunctive treatment after patient discharge:
    • H1 antihistamine: diphenhydramine every 6 hours for 2-3 days; alternative dosing with a nonsedating second generation antihistamine
    • H2 antihistamine: ranitidine twice daily for 2-3 days
    • Corticosteroid: prednisone daily for 2-3 days
  • Follow-up appointment with primary health care professional (after a food-induced anaphylactic reaction), with consideration for additional follow-up with a clinical specialist such as an allergist/immunologist.
( A , III )
* Patients at risk for developing FA are defined as those with a biological parent or sibling with existing, or history of, allergic rhinitis, asthma, AD, or FA.
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Recommendation Grading

Overview

Title

Food Allergy

Authoring Organizations

Publication Month/Year

August 1, 2014

Document Type

Guideline

External Publication Status

Published

Country of Publication

US

Inclusion Criteria

Female, Male, Adolescent, Adult, Child, Infant, Older adult

Health Care Settings

Ambulatory, Childcare center, Correctional facility, Emergency care, Long term care, Medical transportation, School

Intended Users

Nurse, nurse practitioner, physician, physician assistant

Scope

Counseling, Assessment and screening, Diagnosis, Prevention, Management, Treatment

Diseases/Conditions (MeSH)

D000486 - Allergy and Immunology, D005502 - Food, D005512 - Food Hypersensitivity

Keywords

food allergies, food allergy, food allergen, adverse food reactions, eosinophilic esophagitis