Reviews and feature articles
Peanut allergy: Emerging concepts and approaches for an apparent epidemic

https://doi.org/10.1016/j.jaci.2007.07.015Get rights and content

Peanut allergy is typically lifelong, often severe, and potentially fatal. Because reactions can occur from small amounts, the allergy presents patients with significant obstacles to avoid allergic reactions. In North America and the United Kingdom, prevalence rates among schoolchildren are now in excess of 1%, framing an increasing public health concern and raising research questions about environmental, immunologic, and genetic factors that may influence outcomes of peanut allergy. This review focuses on recent observations that continue to question the influences of maternal and infant diet on outcomes of peanut allergy, and explore how peanut may be uniquely suited to induce an allergic response. We highlight studies that affect current diagnosis, management, and the nature of advice that can be provided to patients, including the utility of diagnostic tests, doses that elicit reactions, characteristics of reactions from exposure, issues of cross-reactivity, concerns about peanut contamination of manufactured goods, and the natural course of the allergy. Clinical, molecular, and immunologic advances are reviewed, highlighting research discoveries that influence strategies for improved diagnosis, prevention, and treatment. Among the therapeutic strategies reviewed are sublingual and oral immunotherapy, anti-IgE, Chinese herbal medicine, and vaccine strategies.

Section snippets

Clinical insights regarding the epidemic of peanut allergy

Peanut allergy is being described as “epidemic” only in certain countries, an observation that may provide clues toward etiology and prevention. When considering breathlessness as a reported symptom of a reaction to food from among 15 countries, peanut was identified as the most common food only for the United States.16 The estimated rate of peanut allergy in France is 0.3% to 0.75%17; in Denmark it is 0.2% to 0.4%18; and in a cross-sectional study from Israel, peanut allergy diagnosed by

Present and future diagnostic strategies/natural course

The clinician may be faced with diagnosing peanut allergy in several diverse circumstances: a patient who had an apparent reaction to peanut (clinical history), a child who has not ingested peanut but was tested for peanut IgE because of other food allergies or atopic disease (no ingestion history), or a previously diagnosed child who may have outgrown the allergy. Serum peanut-specific IgE or skin prick tests (SPTs) are primary modalities to determine sensitization and have a major role in

Clinical observations that affect management

The general treatment for a patient diagnosed with peanut allergy is to avoid the food and have an emergency plan in place to treat an allergic reaction/anaphylaxis. The plan typically includes prescription of self-injectable epinephrine83; resources for families are available through the Food Allergy & Anaphylaxis Network (www.foodallergy.org) and similar organizations in several other countries. However, the noted severity of peanut allergy, the young age of children affected, and the

Insights from molecular and immunologic characterization

As noted in this article's Table E2 in the Online Repository at www.jacionline.org, the International Union of Immunological Societies Nomenclature Sub-committee recognizes 8 allergenic proteins in peanuts, although Ara h 3 and Ara h 4 are nearly identical isoforms and Ara h 6 is highly homologous to Ara h 2.103, 104 The 3 major allergens, Ara h 1-3, are comprised of a vicilin, conglutin, and glycinin seed storage proteins, respectively.104 Two of the 8 identified peanut allergens are not

Future therapeutic options

Currently, the only proven therapy for the treatment of peanut allergy, and food allergy in general, is strict avoidance of the peanut-containing foods and education of patients to recognize and treat allergic reactions caused by accidental exposure.23 Attempts at standard subcutaneous immunotherapy have been abandoned because of overwhelming adverse reactions and marginal efficacy.121 As indicated in Table II, immunotherapeutic approaches have more recently focused on 2 main strategies:

Conclusion

Peanut allergy appears to be increasing, and we are just beginning to recognize potential genetic, environmental, and immunologic influences on the development and progression of the disease. Recent studies have refined our understanding of the natural course of peanut allergy and have provided insights for improved diagnosis, management, and patient education. Molecular characterization and clinical-epidemiologic studies continue to increase our understanding of risk factors and present

References (143)

  • J.W. Yu et al.

    Accidental ingestions in children with peanut allergy

    J Allergy Clin Immunol

    (2006)
  • S.H. Sicherer

    Clinical update on peanut allergy

    Ann Allergy Asthma Immunol

    (2002)
  • S.H. Sicherer et al.

    Food allergy

    J Allergy Clin Immunol

    (2006)
  • J. Wang et al.

    Food allergen sensitization in inner-city children with asthma

    J Allergy Clin Immunol

    (2005)
  • I. Kull et al.

    Early-life supplementation of vitamins A and D, in water-soluble form or in peanut oil, and allergic diseases during childhood

    J Allergy Clin Immunol

    (2006)
  • C.A. Camargo et al.

    Regional differences in EpiPen prescriptions in the United States: the potential role of vitamin D

    J Allergy Clin Immunol

    (2007)
  • E. Untersmayr et al.

    The effects of gastric digestion on codfish allergenicity

    J Allergy Clin Immunol

    (2005)
  • S.H. Sicherer et al.

    Genetics of peanut allergy: a twin study

    J Allergy Clin Immunol

    (2000)
  • W.G. Shreffler et al.

    Lack of association of HLA class II alleles with peanut allergy

    Ann Allergy Asthma Immunol

    (2006)
  • N. Omata et al.

    Ovalbumin-specific IgE modulates ovalbumin-specific T-cell response after repetitive oral antigen administration

    J Allergy Clin Immunol

    (2005)
  • J.D. de Jonge et al.

    The importance of dietary control in the development of a peanut allergy model in Brown Norway rats

    Methods

    (2007)
  • J. Rowe et al.

    Prenatal versus postnatal sensitization to environmental allergens in a high-risk birth cohort

    J Allergy Clin Immunol

    (2007)
  • J.J. Liem et al.

    The risk of developing food allergy in premature or low-birth-weight children

    J Allergy Clin Immunol

    (2007)
  • S.J. Maleki et al.

    The major peanut allergen, Ara h 2, functions as a trypsin inhibitor, and roasting enhances this function

    J Allergy Clin Immunol

    (2003)
  • K. Beyer et al.

    Effects of cooking methods on peanut allergenicity

    J Allergy Clin Immunol

    (2001)
  • L. Pons et al.

    Soy immunotherapy for peanut-allergic mice: modulation of the peanut-allergic response

    J Allergy Clin Immunol

    (2004)
  • D. Mittag et al.

    Ara h 8, a Bet v 1-homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy

    J Allergy Clin Immunol

    (2004)
  • S.H. Sicherer 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)
  • S.J. Arbes et al.

    Prevalences of positive skin test responses to 10 common allergens in the US population: results from the third National Health and Nutrition Examination Survey

    J Allergy Clin Immunol

    (2005)
  • H.A. Sampson et al.

    Relationship between food-specific IgE concentrations and the risk of positive food challenges in children and adolescents

    J Allergy Clin Immunol

    (1997)
  • H.A. Sampson

    Utility of food-specific IgE concentrations in predicting symptomatic food allergy

    J Allergy Clin Immunol

    (2001)
  • T.T. Perry et al.

    The relationship of allergen-specific IgE levels and oral food challenge outcome

    J Allergy Clin Immunol

    (2004)
  • G. Roberts et al.

    Diagnosing peanut allergy with skin prick and specific IgE testing

    J Allergy Clin Immunol

    (2005)
  • M.H. Ho et al.

    Diagnostic accuracy of skin prick testing in children with tree nut allergy

    J Allergy Clin Immunol

    (2006)
  • F. Rance et al.

    Improved screening for peanut allergy by the combined use of skin prick tests and specific IgE assays

    J Allergy Clin Immunol

    (2002)
  • J.H. Savage et al.

    The natural history of peanut allergy-extending our knowledge beyond childhood

    J Allergy Clin Immunol

    (2007)
  • D.M. Fleischer et al.

    The natural progression of peanut allergy: resolution and the possibility of recurrence

    J Allergy Clin Immunol

    (2003)
  • D.M. Fleischer et al.

    Peanut allergy: recurrence and its management

    J Allergy Clin Immunol

    (2004)
  • T.T. Perry et al.

    Risk of oral food challenges

    J Allergy Clin Immunol

    (2004)
  • G.W. Palmer et al.

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

    Clin Immunol

    (2005)
  • C. Astier et al.

    Predictive value of skin prick tests using recombinant allergens for diagnosis of peanut allergy

    J Allergy Clin Immunol

    (2006)
  • W.G. Shreffler et al.

    Microarray immunoassay: association of clinical history, in vitro IgE function, and heterogeneity of allergenic peanut epitopes

    J Allergy Clin Immunol

    (2004)
  • H.A. Sampson et al.

    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

    J Allergy Clin Immunol

    (2006)
  • K. Beyer et al.

    Identification of four major sesame seed allergens by 2D-proteonomics and Edman sequencing: seed storage proteins as common food allergens

    J Allergy Clin Immunol

    (2002)
  • M.P. de Leon et al.

    IgE cross-reactivity between the major peanut allergen Ara h 2 and tree nut allergens

    Mol Immunol

    (2007)
  • M. Wensing et al.

    Patients with anaphylaxis to pea can have peanut allergy caused by cross-reactive IgE to vicilin (Ara h 1)

    J Allergy Clin Immunol

    (2003)
  • K.A. Peeters et al.

    Lupine allergy: not simply cross-reactivity with peanut or soy

    J Allergy Clin Immunol

    (2007)
  • D.A. Moneret-Vautrin et al.

    Cross-allergenicity of peanut and lupine: the risk of lupine allergy in patients allergic to peanuts

    J Allergy Clin Immunol

    (1999)
  • S.L. Taylor et al.

    Factors affecting the determination of threshold doses for allergenic foods: how much is too much?

    J Allergy Clin Immunol

    (2002)
  • M. Wensing et al.

    The distribution of individual threshold doses eliciting allergic reactions in a population with peanut allergy

    J Allergy Clin Immunol

    (2002)
  • Cited by (299)

    • Peanut allergy: New insights

      2023, Journal de Pediatrie et de Puericulture
    • Groundnut Kernel Transcriptome

      2020, Comprehensive Foodomics
    View all citing articles on Scopus

    (Supported by an unrestricted educational grant from Genentech, Inc. and Novartis Pharmaceuticals Corporation)

    Section editors: Donald Y. M. Leung, MD, PhD, and Dennis K. Ledford, MD

    Disclosure of potential conflict of interest: H. A. Sampson has consulting interests with Allertein and the Food Allergy Initiative; owns stock in Allertein; has patent licensing arrangements with Allertein, Mount Sinai, and other universities; has received grant support from the National Institutes of Health and the Food Allergy Initiative; and served as an expert witness in peanut allergy litigation 3 to 4 years ago. S. H. Sicherer has declared that he has no conflict of interest.

    View full text