by EBSCO Medical Review Board
(Allergy, Peanut; Nut Allergy; Allergy, Nut)


A peanut allergy is an abnormal response to peanuts. It can be mild or deadly.


It can happen when a person is exposed to peanut proteins. The body mistakes the proteins as being harmful. This makes the immune system send chemicals into the blood that cause the response to happen.

Exposure to peanuts can happen by:

  • Eating peanuts, foods with peanuts, or foods that were around peanuts
  • Touching peanuts
  • Breathing in bits of peanuts, such as peanut flour

Risk Factors

Peanut allergy often starts when a person is a child. It may also start or carry on when a person is an adult. Things that may put you at risk are:

  • Other allergies, such as eczema or hay fever
  • Having people in your family who have allergies
  • Delayed start to eating peanuts during childhood


Problems may be:

  • An itchy skin rash
  • Swelling of the lips, mouth, or throat
  • Coughing or wheezing
  • A change in voice
  • Belly cramps
  • Diarrhea
  • Vomiting
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Anaphylaxis is a response that can be deadly. It may cause:

  • Problems breathing
  • Chest tightness
  • Pale skin or blue skin
  • Lightheadedness
  • Loss of consciousness


You will be asked about your symptoms and health history. A physical exam will be done.

You will be tested with a:

  • Skin prick test to look for a skin response when exposed to peanut proteins
  • Blood test to look for an antibody that shows up when you are exposed to peanut proteins

You may need to see a doctor who treats allergies.


People with a severe response may need medical care right away.

A mild peanut allergy can be managed. Options are:

Avoid Peanuts

The best way to manage this allergy is to avoid peanuts, foods with peanuts, and foods that may have been around peanuts. Always read food labels. Do this even if you do not think a food has peanuts in it. Most labels will state whether the factory where a food was made also works with peanuts. Always ask for the items in homemade foods to check peanuts or peanut oil. Ask if the item was made with kitchen tools that have come in contact with peanuts.


Medicine can ease symptoms. It should only be taken if a person is exposed to peanuts by accident. They may be:

  • Antihistamines to decrease swelling and itching
  • Corticosteroids to treat severe swelling and itching

People with severe reactions may need epinephrine. It is injected into the thigh. It needs to be carried at all times.


To lower the chance of peanut allergy:

  • Women who are pregnant and do not have a peanut allergy may want to eat peanuts.
  • Babies at high risk of peanut allergy should be introduced to peanuts between ages 4 and 11 months. Babies with eczema or egg allergy should see an allergist before having peanuts. They may already be allergic.


American Academy of Allergy, Asthma & Immunology 

Food Allergy Research & Education 


Allergy Canada 

Health Canada 


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Anaphylaxis. EBSCO DynaMed website. Available at: . Updated March 22, 2019. Accessed September 18, 2019.

Fleischer DM, Sichere S, Greenhawt M, et al. Consensus communication on early peanut introduction and the prevention of peanut allergy in high-risk infants. Pediatrics. 2015;136(3):600-604.

Nut and peanut allergy. Kids Health—Nemours Foundation website. Available at: Updated August 2018. Accessed September 18, 2019.

Peanut allergy. American College of Allergy, Asthma & Immunology website. Available at: Updated March 14, 2019. Accessed September 18, 2019.

Peanut allergy. EBSCO DynaMed website. Available at: . Updated May 14, 2019. Accessed September 18, 2019.

Peanut allergy. FARE—Food Allergy Research & Education website. Available at: Accessed September 18, 2019.

1/2/2014 DynaMed Systematic Literature Surveillance : Frazier A, Camargo C, Malspeis S, Willett WC, Young MC. Prospective study of peripregnancy consumption of peanuts or tree nuts by mothers and the risk of peanut or tree nut allergy in their offspring. JAMA Pediatr. 2013;168(2):156-162.

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