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(Allergy, Peanut; Nut Allergy; Allergy, Nut)


A peanut allergy occurs when the body responds abnormally to peanuts. The reaction may range from mild to life-threatening. Even a small amount of peanuts can lead to a serious reaction.

This condition may be serious. It requires care from a doctor.


The allergy occurs when your body is exposed to peanut proteins. The body mistakes the proteins as harmful substances, and the immune system releases chemicals into the bloodstream, causing symptoms.

Coming in contact with peanuts can occur by:

  • Eating peanuts, foods containing them, or foods that came in contact with them
  • Touching peanuts
  • Inhaling particles containing peanuts, such as peanut flour

Risk Factors

Peanut allergy, like other food allergies , is more common in children. Other factors that may increase your chance of a peanut allergy include:

  • Other allergies, such as food allergy, eczema , or hay fever
  • Personal or family history of allergies
  • Delay in starting peanuts in children's diet after 1 year old.


Peanut allergy may cause:

  • Redness or swelling of the skin— hives
  • Itching or tingling of the mouth and throat
  • Diarrhea
  • Stomach cramps
  • Nausea
  • Vomiting
  • Shortness of breath or wheezing
  • Chest tightness
  • Runny or stuffy nose
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Anaphylaxis is a serious, life-threatening allergic reaction. Anaphylaxis may cause:

  • Closing of airways or swelling of throat, making it very hard to breathe
  • Severe drop in blood pressure
  • Very fast pulse
  • Lightheadedness
  • Loss of consciousness

If you have a serious allergic reaction or are with someone who does, call for emergency medical services right away.


You may be referred to a doctor who specializes in allergies. The doctor will:

  • Ask about your symptoms
  • Take your medical history
  • Do a physical exam

Tests may include:

  • Skin prick test—To look for a skin reaction when exposed to peanut or other specific food particles.
  • Blood test—To look for a specific antibody that is present when you are exposed something that gives you an allergic reaction.

Food Diary

You may be asked to keep a food diary. This means you will write down your experiences with food, such as your eating habits and symptoms. This may help the doctor find out if there are other foodds causing your allergies.

Elimination Diet

You may be placed on an elimination diet to learn which foods may be triggering an allergic reaction. If your doctor thinks you might be allergic to peanuts, you may be asked to remove peanuts from your diet for 1-2 weeks then add them back to your diet to see if you experience any symptoms. The elimination diet is only done under a doctor’s supervision.


Talk with your doctor about the best treatment plan for you. Options include:

Avoid Peanuts

The best treatment is to avoid peanuts, foods containing them, and foods that may have been exposed to them. Always read ingredient labels, even if you do not think the food contains peanuts. Most food labels will state whether the factory where a food was made also processes peanuts. If offered homemade foods, always ask about the ingredients to check for the presence of peanuts or peanut oil.


If you do have a mild allergic reaction, you may be able to take antihistamines to reduce symptoms, like itching or hives. Talk with your doctor about medications that are right for you. These medications are only used if you are accidently exposed to peanut-containing foods. They should not be used so you can eat them.

Epinephrine Injection

For severe allergic reactions, you may need to inject yourself with epinephrine. Epinephrine is injected using an auto-injector (EpiPen, Twinject), which contains a syringe, needle, and a dose of the the medication. You inject the medication into your thigh. You should carry an auto-injector with you at all times.

If you have a severe reaction, call for emergency medical services or go to the nearest emergency room right away, whether you use your injector pen or not.


If you are pregnant and do not have a peanut allergy, you may want to consider consuming peanuts to lower the risk that your child will have a peanut allergy.

In infants at high risk for peanut allergy, introducing peanuts between 4-11 months old may reduce this risk. Infants with early-onset eczema or egg allergy in the first 4-6 months of life should see an allergist before doing this, in case they are already allergic to peanuts as well.

To help reduce your chance of a reaction to peanuts:

  • Avoid peanuts, peanut-containing products, and foods that were exposed to peanuts. For instance, when placing an order at a restaurant, ask the server if the dish contains peanuts or is cooked with items (sauces or oils) that may contain peanuts. You might also be allergic to tree nuts such as almond, walnut, pecan, or cashews. Talk to your doctor about the risk.
  • Read food labels and other labels, such as medications, make-up, or face cream labels. You never know what items may contain peanut productss.

Here are some foods that may contain peanuts or may have been made in factories that process peanuts:

  • Cookies
  • Pastries
  • Ice cream
  • Energy bars
  • Cereal
  • Bread
  • Salad dressing
  • Chocolate candies
  • Nut butters and oils
  • Sauces and gravies
  • Vegetarian food products, such as veggie burgers

The list may be endless. This is why it is very important to be aware of what you are eating or come in contact with. Even the smallest amount of peanut protein can trigger a life-threatening response.


American Academy of Allergy, Asthma & Immunology 

FARE—Food Allergy Research & Education 


Allergy Asthma Information Association 

Calgary Allergy Network 


Anaphylaxis. EBSCO DynaMed Plus website. Available at:  . Updated August 22, 2017. Accessed October 2, 2017.

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.

Living with food allergies. Asthma and Allergy Foundation of America website. Available at: Updated July 2015. Accessed October 2, 2017.

Nut and peanut allergy. Kids Health—Nemours Foundation website. Available at: Updated October 2014. Accessed October 2, 2017.

Peanut allergy. American College of Allergy, Asthma & Immunology website. Available at: Accessed October 2, 2017.

Peanut allergy. EBSCO DynaMed Plus website. Available at:  . Updated January 9, 2017. Accessed October 2, 2017.

Peanut allergy. FARE—Food Allergy Research & Education website. Available at: Accessed October 2, 2017.

1/2/2014 DynaMed Plus 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.

Revision Information

  • Reviewer: EBSCO Medical Review Board Marcin Chwistek, MD
  • Review Date: 09/2018
  • Update Date: 08/18/2016