Journal of Allergy and Clinical Immunology
Work Group report: Oral food challenge testing
Section snippets
Indications for an OFC
An OFC may be indicated to confirm that an allergic or other adverse reaction to a food or food additive exists or that it has resolved. The decision to proceed to OFC is complex and may be influenced by many factors including the patient's medical history, age, past adverse food reactions, skin prick test (SPT) and serum food-specific IgE test results, and concomitant food allergies. The decision is also influenced by the importance of the food to the patient because of its nutritional value,
Risks and benefits of an OFC
An OFC resulting in a clinical reaction is termed a positive or failed challenge, whereas an OFC without a clinical reaction is termed a negative or passed challenge. For the purpose of this document, the authors chose to use positive and negative terminology. There have been no associated deaths from OFC reported in the literature indexed since 1976 in PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi). However, positive OFCs have inherent risks including acute allergic reactions with
Reasons for deferring an OFC
An OFC may be deferred if there is a high likelihood of reacting to the food as predicted by the food reaction history, whether immediate or delayed; levels of serum food-specific IgE antibody; and/or results of quantitative skin prick testing and the patient's age (Table I, Table II). OFC is relatively contraindicated in conditions that increase the risk of severe anaphylaxis, such as a recent convincing anaphylactic reaction to the food or unstable asthma. It would not be recommended to
Types of OFC
There are various types of OFC that may be clinically indicated, including open, single-blind, or double-blind, placebo-controlled. The choice of the type of OFC is based on clinical assessment of the potential for bias in the interpretation of the results (Fig 1).3, 4, 18, 25
Location of OFC
Deciding where to perform an OFC should be based on risk assessment and capacity to treat anaphylactic reactions, and practical aspects such as preparation, administration, and monitoring. Low-risk challenges in cooperative patients are appropriate for the office setting. A physician may choose to perform higher-risk OFC in the office setting based on clinical judgment and expertise, and the availability of materials and support for the treatment of a severe reaction.
The timing, type, and
Food preparation for OFC
The challenge food can be brought from home by the patient or parent for open office OFC, whereas for blind OFC, test material should be provided by a physician to ensure proper masking. The food should be prepared without cross-contamination or contact with other foods to which the patient may react and in a sanitary fashion. Preferably, single-ingredient foods should be used for OFC.
Special attention must be given to the form and degree of rawness of the food selected for an OFC. Thermal
Dosing schedule for OFC
Because the goal of an OFC is to test the patient's tolerance to a specific food in a quantity and form that will be subsequently encountered in the diet, the total quantity tested should approximate the regular, age-appropriate serving size of the food.
Obtaining consent and discussing risks and benefits
Documentation of verbal or written informed consent should be considered. Before conducting a food challenge, outcome, risks, and benefits and the implications and the potential limitations of a negative or positive challenge should be discussed with patients and/or parents. The severity of the reaction during a positive OFC should not be used to estimate the severity of future reactions. Because OFC is stopped at the first objective symptom, an exposure to a larger amount of the food may
Administering an OFC
The OFC should be conducted in a location where food may be heated and measured. A small food scale may be necessary for graduated challenges. To eliminate the risk of allergen cross-contamination, clean disposable plates, cups, utensils, and paper towels are used. The challenge area should be cleaned between challenges. For children, having familiar utensils and favorite cups and plates from home and creating a child-friendly environment can make the challenge experience more enjoyable and
Monitoring and stopping OFC
Before starting the feeding, baseline vital signs—respiratory rate, heart rate, and blood pressure—should be recorded and physical findings should be documented to serve as a reference. Recording a peak flow and spirometry may be considered, especially for patients with asthma (Fig 2). Emergency medications must be readily accessible. For high-risk challenges, it may be prudent to have epinephrine drawn up and kept in the patient's room or in an immediately accessible location and with access
Treating reactions
In case of an allergic reaction to an OFC, treatment should be initiated promptly by the person administering the challenge, according to guidelines for anaphylaxis treatment.125 Vital signs should be obtained as soon as symptoms are noted, but obtaining them should not delay treatment when the reaction appears to require rapid intervention or to be severe. Oral antihistamines are used to treat mild reactions; parenteral antihistamines can be administered via intramuscular or intravenous
Negative OFC
The OFC is negative if the patient tolerates the entire challenge, including the masked and open portions of a blinded OFC and observation period. The patient may be discharged home after at least 1 to 2 hours of observation for the immediate-type reactions and 4 hours for food protein–induced enterocolitis syndrome. Longer observation periods may be necessary in patients with later onset of symptoms in previous reactions, such as gastrointestinal complaints and/or eczema. Depending on the
OFC for research
The following discussion is applicable to OFCs conducted for clinical research. As a result of scientific rigor, the majority of research studies use DBPCFC protocols, in which masking of challenge foods and development of placebo foods is provided by professional dietitians after extensive testing.4, 26, 29 DBPCFC can be used to determine threshold doses for the food industry—for example, for assessment of product contamination with food allergens, for monitoring the accuracy of equipment
Summary
The OFC is a valuable tool in the initial diagnosis and management of adverse food reactions including food allergy. In vivo and in vitro tests of food-specific IgE do not always correlate with clinical reactivity. OFC can be safely conducted under physician supervision, with appropriate precautions, although as noted throughout this article, the potential for serious reactions exists. Allergists/immunologists are particularly well qualified to conduct OFCs to assist patients with correct
References (139)
Objective clinical and laboratory studies of immediate hypersensitivity reactions to foods in asthmatic children
J Allergy Clin Immunol
(1976)- et al.
Food hypersensitivity and atopic dermatitis: evaluation of 113 patients
J Pediatr
(1985) - et al.
Risk-taking and coping strategies of adolescents and young adults with food allergy
J Allergy Clin Immunol
(2006) - et al.
Current approach to the diagnosis and management of adverse reactions to foods
J Allergy Clin Immunol
(2004) - et al.
An expanding evidence base provides food for thought to avoid indigestion in managing difficult dilemmas in food allergy
J Allergy Clin Immunol
(2006) - et al.
Food allergy
J Allergy Clin Immunol
(2006) - et al.
Relationship between food-specific IgE concentrations and the risk of positive food challenges in children and adolescents
J Allergy Clin Immunol
(1997) Utility of food-specific IgE concentrations in predicting symptomatic food allergy
J Allergy Clin Immunol
(2001)- et al.
Diagnosing peanut allergy with skin prick and specific IgE testing
J Allergy Clin Immunol
(2005) - et al.
The atopy patch test in the diagnostic workup of suspected food-related symptoms in children
J Allergy Clin Immunol
(2006)
Skin prick test to egg white provides additional diagnostic utility to serum egg white-specific IgE antibody concentration in children
J Allergy Clin Immunol
The relationship of allergen-specific IgE levels and oral food challenge outcome
J Allergy Clin Immunol
Dose-response in double-blind, placebo-controlled oral food challenges in children with atopic dermatitis
J Allergy Clin Immunol
Masking foods for food challenge: practical aspects of masking foods for a double-blind, placebo-controlled food challenge
J Am Diet Assoc
Randomized, double-blind, cross-over challenge study in 53 subjects reporting adverse reactions to melon (Cucumis melo)
J Allergy Clin Immunology
Development and validation of challenge materials for double-blind, placebo-controlled food challenges in children
J Allergy Clin Immunol
An evaluation of the sensitivity of subjects with peanut allergy to very low doses of peanut protein: a randomized, double-blind, placebo-controlled food challenge study
J Allergy Clin Immunol
Milk-responsive atopic dermatitis is associated with a casein-specific lymphocyte response in adolescent and adult patients
J Allergy Clin Immunol
Hypoallergenicity and efficacy of an amino acid-based formula in children with cow's milk and multiple food hypersensitivities
J Pediatr
The natural history of peanut allergy
J Allergy Clin Immunol
Evaluating the effect of food processing on the potential human allergenicity of novel proteins: international workshop report
Food Chem Toxicol
Anaphylactic reactions to raw eggs after negative challenges with cooked eggs
J Allergy Clin Immunol
Allergenic activity of heated and ovomucoid-depleted egg white
J Allergy Clin Immunol
Clinical reactivity to beef in children allergic to cow's milk
J Allergy Clin Immunol
Anaphylaxis to cow's milk and beef meat proteins
Ann Allergy Asthma Immunol
Carrot allergy: double-blinded, placebo-controlled food challenge and identification of allergens
J Allergy Clin Immunol
Fish hypersensitivity, I: in vitro and oral challenge results in fish-allergic patients
J Allergy Clin Immunol
Fish hypersensitivity, II: clinical relevance of altered fish allergenicity caused by various preparation methods
J Allergy Clin Immunol
Allergy to canned tuna
J Allergy Clin Immunol
In vivo assessment with prick-to-prick testing and double-blind, placebo-controlled food challenge of allergenicity of apple cultivars
J Allergy Clin Immunol
Characterization of apple 18 and 31 kd allergens by microsequencing and evaluation of their content during storage and ripening
J Allergy Clin Immunol
Clinical cross-reactivity among foods of the Rosaceae family
J Allergy Clin Immunology
Celery allergy confirmed by double-blind, placebo-controlled food challenge: a clinical study in 32 subjects with a history of adverse reactions to celery root
J Allergy Clin Immunol
Celery allergens in patients with positive double-blind placebo-controlled food challenge
J Allergy Clin Immunol
Adverse reactions to food additives
Ann Allergy Asthma Immunol
Anaphylaxis to carrageenan: a pseudo-latex allergy
J Allergy Clin Immunol
Sulfite-treated lettuce challenges in sulfite-sensitive subjects with asthma
J Allergy Clin Immunol
Multicenter, double-blind, placebo-controlled, multiple-challenge evaluation of reported reactions to monosodium glutamate
J Allergy Clin Immunol
Review of alleged reaction to monosodium glutamate and outcome of a multicenter double-blind placebo-controlled study
J Nutr
Adverse reactions to tartrazine
J Allergy Clin Immunol
Birch pollen-related foods trigger atopic dermatitis in patients with specific cutaneous T-cell responses to birch pollen antigens
J Allergy Clin Immunol
Enterocolitis in low-birth-weight infants associated with milk and soy protein intolerance
J Pediatr
Milk- and soy-induced enterocolitis of infancy
J Pediatr
Clinical features of food-protein-induced enterocolitis syndrome
J Pediatr
Food protein-induced enterocolitis syndrome: case presentations and management lessons
J Allergy Clin Immunol
Risk of oral food challenges
J Allergy Clin Immunol
The natural progression of peanut allergy: resolution and the possibility of recurrence
J Allergy Clin Immunol
Peanut allergy: recurrence and its management
J Allergy Clin Immunol
Double-blind, placebo-controlled food challenge (DBPCFC) as an office procedure: a manual
J Allergy Clin Immunol
Standardization of food challenges in patients with immediate reactions to foods—position paper from the European Academy of Allergology and Clinical Immunology
Allergy
Cited by (480)
Effectiveness of continuous allergenic food intake for acute food protein–induced enterocolitis syndrome
2024, Journal of Allergy and Clinical Immunology: GlobalEgg allergy and yellow fever vaccination
2024, Jornal de PediatriaUnited States Drug Allergy Registry (USDAR) grading scale for immediate drug reactions
2023, Journal of Allergy and Clinical ImmunologyOutcomes of oral food challenges in a real-world setting, with predictors of outcomes
2023, Annals of Allergy, Asthma and ImmunologySafety of Multifood Oral Immunotherapy in Children Aged 1 to 18 Years at an Academic Pediatric Clinic
2023, Journal of Allergy and Clinical Immunology: In PracticeFood Allergy
2023, Primary Care - Clinics in Office Practice
Supported by the Food Allergy Initiative. The Food Allergy Initiative is a nonprofit corporation dedicated to finding a cure for food allergies by funding food allergy research; it does not conduct scientific research or render medical advice. The opinion in the manuscript reflects that of the authors and not that of the Food Allergy Initiative, and Food Allergy Initiative is not responsible or liable for the information set forth in the manuscript or for any damages that may result from its use.
Disclosure of potential conflict of interest: A. Assa'ad has received research support from GlaxoSmithKline. A. Nowak-Węgrzyn has received research support from the National Institutes of Health. S. L. Bahna has received research support from Genentech/Novartis and CSL Behring. S. H. Sicherer has received research support from the National Institutes of Health/National Institute of Allergy and Infectious Diseases and is a consultant for the Food Allergy Initiative and a medical advisor for the Food Allergy and Anaphylaxis Network. The rest of the authors have declared that they have no conflict of interest.
- ∗
Authors listed alphabetically.