Food allergy: a practice parameter update-2014.

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology (JCAAI). The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Food Allergy: A practice parameter update-2014." This is a complete and comprehensive document at the current time. The medical environment is a changing one, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, ACAAI, and JCAAI. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Oral food challenges in children with a diagnosis of food allergy.

OBJECTIVE: To assess the outcome of oral food challenges in patients placed on elimination diets based primarily on positive serum immunoglobulin E (IgE) immunoassay results. STUDY DESIGN: This is a retrospective chart review of 125 children aged 1-19 years (median age, 4 years) evaluated between January 2007 and August 2008 for IgE-mediated food allergy at National Jewish Health and who underwent an oral food challenge. Clinical history, prick skin test results, and serum allergen-specific IgE test results were obtained. RESULTS: The data were summarized for food avoidance and oral food challenge results. Depending on the reason for avoidance, 84%-93% of the foods being avoided were returned to the diet after an oral food challenge, indicating that the vast majority of foods that had been restricted could be tolerated at discharge. CONCLUSIONS: In the absence of anaphylaxis, the primary reliance on serum food-specific IgE testing to determine the need for a food elimination diet is not sufficient, especially in children with atopic dermatitis. In those circumstances, oral food challenges may be indicated to confirm food allergy status.

National prevalence and risk factors for food allergy and relationship to asthma: results from the National Health and Nutrition Examination Survey 2005-2006.

BACKGROUND: The national prevalence and patterns of food allergy (FA) in the United States are not well understood. OBJECTIVE: We developed nationally representative estimates of the prevalence of and demographic risk factors for FA and investigated associations of FA with asthma, hay fever, and eczema. METHODS: A total of 8203 participants in the National Health and Nutrition Examination Survey 2005-2006 had food-specific serum IgE measured to peanut, cow's milk, egg white, and shrimp. Food-specific IgE and age-based criteria were used to define likely FA (LFA), possible FA, and unlikely FA and to develop estimates of clinical FA. Self-reported data were used to evaluate demographic risk factors and associations with asthma and related conditions. RESULTS: In the United States, the estimated prevalence of clinical FA was 2.5% (peanut, 1.3%; milk, 0.4%; egg, 0.2%; shrimp, 1.0%; not mutually exclusive). Risk of possible FA/LFA was increased in non-Hispanic blacks (odds ratio, 3.06; 95% CI, 2.14-4.36), males (1.87; 1.32-2.66), and children (2.04; 1.42-2.93). Study participants with doctor-diagnosed asthma (vs no asthma) exhibited increased risk of all measures of food sensitization. Moreover, in those with LFA, the adjusted odds ratio for current asthma (3.8; 1.5-10.7) and an emergency department visit for asthma in the past year (6.9; 2.4-19.7) were both notably increased. CONCLUSION: Population-based serologic data on 4 foods indicate an estimated 2.5% of the US population has FA, and increased risk was found for black subjects, male subjects, and children. In addition, FA could be an under-recognized risk factor for problematic asthma.

Work Group report: oral food challenge testing.

Oral food challenges are procedures conducted by allergists/immunologists to make an accurate diagnosis of immediate, and occasionally delayed, adverse reactions to foods. The timing of the challenge is carefully chosen based on the individual patient history and the results of skin prick tests and food specific serum IgE values. The type of the challenge is determined by the history, the age of the patient, and the likelihood of encountering subjective reactions. The food challenge requires preparation of the patient for the procedure and preparation of the office for the organized conduct of the challenge, for a careful assessment of the symptoms and signs and the treatment of reactions. The starting dose, the escalation of the dosing, and the intervals between doses are determined based on experience and the patient's history. The interpretation of the results of the challenge and arrangements for follow-up after a challenge are important. A negative oral food challenge result allows introduction of the food into the diet, whereas a positive oral food challenge result provides a sound basis for continued avoidance of the food.

Managing Food Allergy in Schools During the COVID-19 Pandemic.

In the wake of the COVID-19 pandemic and massive disruptions to daily life in the spring of 2020, in May 2020, the Centers for Disease Control (CDC) released guidance recommendations for schools regarding how to have students attend while adhering to principles of how to reduce the risk of contracting SARS-CoV-2. As part of physical distancing measures, the CDC is recommending that schools who traditionally have had students eat in a cafeteria or common large space instead have children eat their lunch or other meals in the classroom at already physically distanced desks. This has sparked concern for the safety of food-allergic children attending school, and some question of how the new CDC recommendations can coexist with recommendations in the 2013 CDC Voluntary Guidelines on Managing Food Allergy in Schools as well as accommodations that students may be afforded through disability law that may have previously prohibited eating in the classroom. This expert consensus explores the issues related to evidence-based management of food allergy at school, the issues of managing the health of children attending school that are acutely posed by the constraints of an infectious pandemic, and how to harmonize these needs so that all children can attend school with minimal risk from both an infectious and allergic standpoint.

Fatal anaphylaxis to foods: epidemiology, recognition, and prevention.

The inability to accurately predict the severity of future allergic reactions to foods in a given individual coupled with the real--although usually remote--risk of a fatal anaphylactic reaction complicates care and remains a constant source of concern to food-allergic patients, their family members, and health care providers. Current epidemiologic evidence suggests that the incidence of food-induced anaphylaxis is increasing, although confidently approximating the incidence of fatal allergic reactions to foods remains difficult. This article briefly reviews the epidemiology of fatal anaphylactic reactions to foods, discusses factors that may aid in identifying individuals at higher risk, emphasizes important aspects of patient education and prevention, and touches on the psychological impact of having a family member with food allergy.

Conducting an Oral Food Challenge to Peanut in an Infant.

Results from the Learning Early About Peanut trial and its follow-up study suggest that early peanut introduction in the diets of high-risk infants may prevent the development of peanut allergy. Allergy organizations around the world released a unified statement, the Consensus Communication on Early Peanut Introduction and the Prevention of Peanut Allergy in High Risk Infants, in response to results from the Learning Early About Peanut trial, which recommends early introduction of peanut into the diet of those children at greatest risk of development of peanut allergy. As a result, it is expected that practicing allergists will experience an increased demand to perform an oral food challenge (OFC) in infants. Allergists often perform OFCs; however, conducting an OFC in an infant creates unique circumstances that have not been considered in previously published OFC guideline documents. The purpose of this workgroup report is to provide guidance to practitioners regarding the proper approach for conducting a peanut challenge in an infant.

Second symposium on the definition and management of anaphylaxis: summary report--second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network symposium.

There is no universal agreement on the definition of anaphylaxis or the criteria for diagnosis. In July 2005, the National Institute of Allergy and Infectious Disease and Food Allergy and Anaphylaxis Network convened a second meeting on anaphylaxis, which included representatives from 16 different organizations or government bodies, including representatives from North America, Europe, and Australia, to continue working toward a universally accepted definition of anaphylaxis, establish clinical criteria that would accurately identify cases of anaphylaxis with high precision, further review the evidence on the most appropriate management of anaphylaxis, and outline the research needs in this area.

Randomized comparison of the safety of Flublok(®) versus licensed inactivated influenza vaccine in healthy, medically stable adults ≥ 50 years of age.

BACKGROUND: The safety and tolerability of Flublok(®), a purified recombinant hemagglutinin seasonal influenza vaccine, was compared to AFLURIA(®) in a randomized, blinded clinical trial in adults ≥ 50 years of age with attention to hypersensitivity reactions. METHODS: This blinded, randomized trial of healthy adults ≥ 50 years of age compared safety of Flublok vs. AFLURIA with respect to pre-specified possible hypersensitivity: "rash," "urticaria," "swelling" and "non-dependent edema;" solicited reactogenicity and unsolicited adverse events. Subject-reported outcomes were collected for 30 days after vaccination. All adverse event terms were reviewed by physicians blinded to vaccine group, who added other terms possibly reflecting hypersensitivity. Case records of subjects with possible hypersensitivity were adjudicated by independent experts blinded to treatment assignment to identify likely hypersensitivity reactions. Non-inferiority of the incidence of hypersensitivity in the two vaccine groups was pre-defined as an absolute difference with an upper bound of 2-sided 95% confidence limits ≤ 0.015. RESULTS: A total of 2640 subjects were enrolled, evenly split in age cohorts of 50-64 and ≥ 65 years. Fifty-two subjects reported at least one term possibly representing hypersensitivity, with a slight imbalance of 31 on Flublok and 21 on AFLURIA. The adjudicators determined that six and four subjects on Flublok and AFLURIA, respectively, likely met clinical criteria for hypersensitivity, yielding a difference in incidence between the two vaccine groups of 0.15% (upper bound of 2-sided 95% CI=0.9%). Reactogenicity and overall adverse event profiles were similar across both vaccines. CONCLUSIONS: Flublok was non-inferior to AFLURIA in adults ≥ 50 years of age with respect to expert-adjudicated events of likely hypersensitivity during 30 days following vaccination (Sponsored by Protein Sciences Corporation; ClinicalTrials.gov number NCT01825200).

RBL cells expressing human Fc epsilon RI are a sensitive tool for exploring functional IgE-allergen interactions: studies with sera from peanut-sensitive patients.

Rat basophilic leukemia cells (RBL SX-38) express the alpha, beta, and gamma chains of human Fc epsilon RI. Following sensitization with IgE from a subset of allergic human donors, these cells can be triggered by exposure to anti-IgE or to very low concentrations of specific allergens. We examined 18 sera from patients who were highly sensitive to peanuts by history and had anti-peanut IgE by in vitro testing. The ability of these sera to sensitize the RBL SX-38 cells for degranulation with peanut allergens correlates very well with the absolute amount of anti-peanut IgE (r=0.95; p<0.001). The most effective sera contained at least 50 kU/l of total IgE and at least 15 kU/l of peanut-specific IgE. RBL SX-38 cells sensitized with these sera degranulated optimally upon exposure to anti-IgE (net degranulation of 40+/-8%, means+/-S.D.; n=8) and to a 10(5)-10(6) dilution of crude peanut extract (CPE) (37+/-7% net degranulation; 93+/-13% of that seen with anti-IgE). This assay is quite sensitive. Cells sensitized with selected sera are activated by exposure to a 1:10(7) dilution of the CPE containing picogram amounts of peanut allergens. This assay is also quite specific. Cells sensitized with sera from patients with anti-peanut IgE and no detectable IgE against soybean, walnut or grass pollen did not degranulate following exposure to these latter antigens. The converse was also true; cells sensitized with sera from patients without anti-peanut IgE did not react to peanut. These data demonstrate that RBL cells expressing human Fc epsilon RI form the basis of a useful model system for the detection of allergens and for the study of IgE-allergen interactions.

Update on the clinical features of food-induced anaphylaxis.

Food-induced anaphylaxis has become the leading cause of anaphylactic reactions that occur outside hospital. We introduce the present review with a definition of food-induced anaphylaxis, including its prevalence and proposed etiology. Second, we discuss an entity that is increasingly being recognized: exercise-induced food anaphylaxis, which may be triggered by specific foods or at times where no specific food has been identified. Third, we review current attempts to identify specific food antigens that are responsible for anaphylaxis to well-known triggers (i.e. peanut, as well as more unusual antigens). Fourth, we discuss current treatment options available (i.e. patient education, food avoidance, acute symptom recognition, and early use of self-administered epinephrine). Additionally, we discuss outcome data regarding the morbidity and mortality related to food allergy and anaphylaxis. Finally, information regarding experimental immunomodulatory therapy is presented.

Second symposium on the definition and management of anaphylaxis: summary report--Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network symposium.

There is no universal agreement on the definition of anaphylaxis or the criteria for diagnosis. In July 2005, the National Institute of Allergy and Infectious Disease and Food Allergy and Anaphylaxis Network convened a second meeting on anaphylaxis, which included representatives from 16 different organizations or government bodies, including representatives from North America, Europe, and Australia, to continue working toward a universally accepted definition of anaphylaxis, establish clinical criteria that would accurately identify cases of anaphylaxis with high precision, further review the evidence on the most appropriate management of anaphylaxis, and outline the research needs in this area.

Comparative potency of Ara h 1 and Ara h 2 in immunochemical and functional assays of allergenicity.

To assess the relative potency of the major peanut allergens, Ara h 1 and Ara h 2, we examined the relative ability of purified proteins to bind IgE on immunoblots, to cross-link allergen specific IgE in an in vitro assay of degranulation based on RBL SX-38 cells, and to bind IgE in the ImmunoCap assay. Sera from 12 highly sensitive, peanut allergic patients were studied in all assays. IgE immunoblots with crude peanut extracts showed binding of IgE to multiple bands including the 63 kDa and 17-19 kDa bands that contain Ara h 1 and Ara h 2, respectively. In the functional assay, Ara h 2 was more potent than Ara h 1 in 11 of 12 sera tested with a median potency that was 52.5-fold more than Ara h 1 (P < 0.005). Contrary to findings with the functional assay, IgE immunoblots with purified Ara h 1 and Ara h 2 showed substantially lighter binding of IgE to Ara h 2 compared with Ara h 1 (P = 0.02). The ImmunoCap assay gave intermediate results with slightly more IgE binding to Ara h 2 than to Ara h 1 (P = 0.005). In conclusion, Ara h 2 is a very potent allergen and is much more potent than Ara h 1 for most sera using an in vitro assay of IgE cross-linking and cell activation. This finding is different from what was predicted based on immunoblots or with the ImmunoCap assay.

Diagnostic evaluation.

The diagnosis and management of adverse food reactions is a challenge for pediatricians and other primary care providers. Children of all ages may present with a variety of symptoms that parents have attributed to constituents of the diet. An approach has been devised to aid pediatricians in the evaluation of these children. The process begins with a detailed history. This history may be used to classify the problem into categories of symptoms and possible mechanisms. When common food offenders are suspected of causing symptoms, it is reasonable to obtain in vitro tests that may then be used to decide whether elimination of certain foods is indicated and whether a referral to an allergist is needed. Using this approach, the physician may be able to identify children who are experiencing food-allergic symptoms and aid frustrated families in dealing with problems that have not had apparent solutions. The application of specific testing and the assessment of the results are discussed. Also reviewed are the techniques used by allergists so that pediatricians may help families understand procedures that will be recommended and performed.

Multicenter study of emergency department visits for food allergies.

BACKGROUND: Relatively little is known about the characteristics of patients who visit the emergency department (ED) for an acute allergic reaction. Although anaphylaxis guidelines suggest treatment with epinephrine, teaching about self-injectable epinephrine, and referral to an allergist, current ED management remains uncertain. OBJECTIVE: The objective of this study was to describe the management of food-related acute allergic reactions. METHODS: The Multicenter Airway Research Collaboration performed a chart review study in 21 North American EDs. Investigators reviewed a random sample of 678 charts of patients who presented with food allergy (International Classification of Diseases-ninth revision codes 693.1, 995.0, 995.3, and 995.60-995.69). RESULTS: Patients had an average age of 29 years; the cohort was 57% female and 40% white. A variety of foods provoked the allergic reaction, including nuts (21%), crustaceans (19%), fruit (12%), and fish (10%). Although exposure to these foods can be life threatening, only 18% of patients came to the ED by ambulance. In the ED, 72% of patients received antihistamines, 48% received systemic corticosteroids, and 16% received epinephrine; 33% received respiratory treatments such as inhaled albuterol. Among patients with severe reactions (55% of total), 24% received epinephrine. Overall, 97% of patients were discharged to home. At ED discharge, 16% of patients were prescribed self-injectable epinephrine, and 12% were referred to an allergist. CONCLUSIONS: Although guidelines suggest specific approaches for the management of acute allergic reactions, ED concordance for food allergy appears low. These findings support a new collaboration between professional organizations in allergy and emergency medicine and the development of educational programs and materials for ED patients and staff.