What is Peanut Allergy?

NewsGuard 100/100 Score

Peanut allergy is one of the most common food allergies and, in the Western world, is thought to be prevalent in up to 1 in 200 individuals in some populations. In fact, studies have suggested that peanut allergy in American children younger than five years doubled in prevalence between 1998 and 2003. In the United Kingdom, around 0.4 to 0.6% of the population suffers from peanut allergies.

Studies have shown that peanut allergy makes up about 28% of all food allergies in children and it develops before the child reaches their first birthday in around half of cases. The allergy rarely develops in children older than 15 years.


Some of the symptoms of peanut allergy include:

  • A red, raised, itchy rash called urticaria
  • Swelling of the face, lips, eyes, mouth and throat, called angioedema
  • Constriction of the airways leading to tightness of the chest, wheezing and flare-ups of asthma
  • Runny nose, watering and red eyes (allergic conjunctivitis) and nasal congestion.
  • Nausea, vomiting and diarrhea
  • Peanut-containing oils, creams, lotions or cosmetics may cause contact dermatitis and eczema.


Anaphylaxis is a very serious and life threatening allergic reaction that leads to a severe drop in blood pressure, constriction of the airways and swelling of the larynx that can cause choking. Urticaria and angioedema may be also be present.

Mechanism of peanut allergy

Around 70% of children with peanut allergy develop the allergy on their first known exposure to peanuts. However, this has usually been preceded by an unknown exposure to the nut when no noticeable symptoms were triggered but the child became sensitized or primed for allergy.

On this original, first exposure, the immune system reacts to proteins in the peanuts by producing the antibody immunoglobulin E (IgE) which binds to receptors present on mast cells and basophils. Subsequent exposure to peanut leads to an inflammatory response governed by these cells, as the peanut protein causes the IgE/receptor complexes to cross link and activate the release of the inflammatory mediators (eg histamine) inside them. Histamine and other inflammatory mediators then trigger the symptoms of an allergic reaction.

Examples of unnoticed first exposure to the peanut protein include:

  • Exposure of fetus to peanut protein consumed by the mother
  • The presence of the allergen in the mother's breast milk
  • Exposure to the peanut extract found in oils and lotions worn by other individuals

Diagnosis and treatment

  • Diagnosis of peanut allergy involves a detailed evaluation of a patient's diet history and the severity and duration of their symptoms on exposure to peanuts. Next, a skin test for the allergy may be performed or a blood sample taken to check for IgE. In rare cases, a positive challenge test may be performed, where the peanut protein is administered to the patient to examine his or her allergic reaction.
  • The most common approach to managing peanut allergy is complete avoidance of the peanut protein. This can be difficult to achieve and requires constant vigilance with regard to reading the labels of any products that may contain nuts.

Further Reading

Last Updated: Jun 9, 2023

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Mandal, Ananya. (2023, June 09). What is Peanut Allergy?. News-Medical. Retrieved on May 21, 2024 from https://www.news-medical.net/health/What-is-Peanut-Allergy.aspx.

  • MLA

    Mandal, Ananya. "What is Peanut Allergy?". News-Medical. 21 May 2024. <https://www.news-medical.net/health/What-is-Peanut-Allergy.aspx>.

  • Chicago

    Mandal, Ananya. "What is Peanut Allergy?". News-Medical. https://www.news-medical.net/health/What-is-Peanut-Allergy.aspx. (accessed May 21, 2024).

  • Harvard

    Mandal, Ananya. 2023. What is Peanut Allergy?. News-Medical, viewed 21 May 2024, https://www.news-medical.net/health/What-is-Peanut-Allergy.aspx.


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
New study reveals increased risk of allergic diseases after COVID-19 infection