White paper peanut allergy—part 2: Diagnosis of peanut allergy with special emphasis on molecular component diagnostics

Summary Background Peanut allergy is an immunoglobulin E (IgE)-mediated immune response that usually manifests in childhood and can range from mild skin reactions to anaphylaxis. Since quality of life maybe greatly reduced by the diagnosis of peanut allergy, an accurate diagnosis should always be made. Methods A selective literature search was performed in PubMed and consensus diagnostic algorithms are presented. Results Important diagnostic elements include a detailed clinical history, detection of peanut-specific sensitization by skin prick testing and/or in vitro measurement of peanut (extract)-specific IgE and/or molecular components, and double-blind, placebo-controlled food challenge as the gold standard. Using these tools, including published cut-off values, diagnostic algorithms were established for the following constellations: 1) Suspicion of primary peanut allergy with a history of immediate systemic reaction, 2) Suspicion of primary peanut allergy with questionable symptoms, 3) Incidental findings on sensitization testing and peanut ingestion so far or 4) Suspicion of pollen-associated peanut allergy with solely oropharyngeal symptoms. Conclusion The most important diagnostic measures in determining the diagnosis of peanut allergy are clinical history and detection of sensitizations, also via component-based diagnostics. However, in case of unclear results, the gold standard—an oral food challenge—should always be used.

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Is Ara h 2 indeed the best predictor for peanut allergy in Dutch children?

Diagnosis ◽

10.1515/dx-2015-0032 ◽

2016 ◽

Vol 3 (1) ◽

pp. 31-35 ◽

Cited By ~ 3

Author(s):

Mirjam Schots ◽

Amerik C. de Mol ◽

Henricus J. Vermeer ◽

Yvonne M. Roosen ◽

Aldonse W. Vriesman

Keyword(s):

Prediction Model ◽

Peanut Allergy ◽

Immunoglobulin E ◽

Food Challenge ◽

Discriminative Ability ◽

Double Blind ◽

Ara H 2 ◽

Receiver Operating Characteristic Curves ◽

Specific Immunoglobulin E ◽

Predicting Factor

AbstractSpecific immunoglobulin E to Ara h 2 (sIgE to Ara h 2) is described as an upcoming predicting factor for diagnosing peanut allergy in children. The gold standard for diagnosing peanut allergy is a double blind placebo controlled food challenge, however this is time consuming and potentially harmful. We investigate Ara h 2 as a preliminary less invasive diagnostic tool for diagnosing peanut allergy in a general population of peanut sensitized children.Children (n=52) with peanut sensitization were retrospectively included. An oral food challenge (OFC) confirmed peanut allergy or tolerance, as primary outcome. Individual candidate predictors were identified by univariate regression analysis and used in a prediction model. Different cut-off values were obtained and receiver operating characteristic curves were plotted.Multivariate analyses resulted in Ara h 2 as best predictor, with a discriminative ability of 0.87 (95% confidence interval, 0.77–0.97). Sensitivity and specificity of 55% and 95%, respectively, were found for a sIgE to Ara h 2 cut-off value of 4.25 kU/L. The highest positive predictive value of 100% was reached at 5.61 kU/L. No absolute relation was found between the value of Ara h 2 and the severity of the reaction during OFC.This study developed a prediction model in which sIgE to Ara h 2 was the best predictor for peanut allergy in sensitized children in a general hospital. Therefore depending on the history and the Ara h 2 results, an OFC is not always needed to confirm the diagnosis.

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Food Allergy: Unproven diagnostics and therapeutics

Journal of Food Allergy ◽

10.2500/jfa.2020.2.200013 ◽

2020 ◽

Vol 2 (1) ◽

pp. 91-94

Author(s):

Megan F. Patterson ◽

Stacy L. Dorris

Keyword(s):

Food Allergy ◽

Adverse Reactions ◽

Immunoglobulin E ◽

Skin Prick Testing ◽

Scientific Evidence ◽

Food Challenge ◽

Clinical History ◽

Specific Ige ◽

Therapeutic Modalities ◽

Diagnostic Modalities

Food allergy or intolerance is often attributed by patients as the cause of many symptoms unknown to be directly related to food ingestion. For immunoglobulin E (IgE) mediated food allergy, diagnostic modalities are currently limited to the combination of clinical history, evidence of sensitization with food-specific IgE testing and skin-prick testing, and oral food challenge. Many patients find an appeal in the promise of identification of the etiology of their symptoms through alternative food allergy or intolerance diagnostic modalities. These patients may seek guidance from allergists or their general providers as to the legitimacy of these tests or interpretation of results. These tests include food-specific serum IgG or IgG4 testing, flow cytometry to measure the change in leukocyte volume after exposure to food, intradermal or sublingual provocation-neutralization, electrodermal testing, applied kinesiology, hair analysis, and iridology. In addition, there are some unconventional therapeutic modalities for adverse reactions to foods, including rotary diets. None of these have been supported by scientific evidence, and some even carry the risk of severe adverse reactions. It is important that we offer our patients evidence-based, accurate counseling of these unproven modalities by understanding their methods, their paucity of credible scientific support, and their associated risks.

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Prevention of food allergy

Allergy and Asthma Proceedings ◽

10.2500/aap.2019.40.4269 ◽

2019 ◽

Vol 40 (6) ◽

pp. 450-452 ◽

Cited By ~ 1

Author(s):

Ashley L. Devonshire ◽

Rachel Glick Robison

Keyword(s):

Food Allergy ◽

Peanut Allergy ◽

Immunoglobulin E ◽

Skin Prick Testing ◽

Clinical Manifestations ◽

Conclusive Evidence ◽

Severe Atopic Dermatitis ◽

Early Introduction ◽

Infant Diet ◽

Specific Immunoglobulin E

Primary prevention and secondary prevention in the context of food allergy refer to prevention of the development of sensitization (i.e., the presence of food-specific immunoglobulin E (IgE) as measured by skin-prick testing and/or laboratory testing) and sensitization plus the clinical manifestations of food allergy, respectively. Until recently, interventions that target the prevention of food allergy have been limited. Although exclusive breast-feeding for the first 6 months of life has been a long-standing recommendation due to associated health benefits, recommendations regarding complementary feeding in infancy have significantly changed over the past 20 years. There now is evidence to support early introduction of peanut into the diet of infants with egg allergy, severe atopic dermatitis, or both diagnoses, defined as high risk for peanut allergy, to try to prevent development of peanut allergy. Although guideline-based recommendations are not available for early introduction of additional allergenic foods, this topic is being actively studied. There is no evidence to support additional dietary modification of the maternal or infant diet for the prevention of food allergy. Similarly, there is no conclusive evidence to support maternal avoidance diets for the prevention of food allergy.

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Oral immunotherapy for treatment of peanut allergy

Journal of Investigative Medicine ◽

10.1136/jim-2020-001422 ◽

2020 ◽

Vol 68 (6) ◽

pp. 1152-1155

Author(s):

Joan H Dunlop

Keyword(s):

Food Allergy ◽

Peanut Allergy ◽

Food Challenge ◽

Oral Immunotherapy ◽

Peanut Protein ◽

Subcutaneous Immunotherapy ◽

Double Blind ◽

The Us ◽

Allergy Prevalence

The US Food and Drug Administration’s approval of a peanut oral immunotherapy product in January 2020 is a landmark development in the field of food allergy therapy. While food allergy prevalence has been increasing, this product is the first approved therapy for food allergy. Oral immunotherapy has many similarities to subcutaneous immunotherapy and drug desensitization protocols, but does not lead to sustained unresponsiveness. The studies leading to approval of the Palforzia product demonstrated increase in the amount of peanut protein able to be consumed, with 67% of subjects randomized to the treatment arm able to consume 600 mg of peanut protein in double-blind placebo-controlled food challenge at study exit. However, side effects are an important consideration, and dropout rates in studies of Palforzia ranged from 11% to 21%. Postmarketing surveillance of this product will be critical in assessing its long-term risks and benefits.

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