Overview

Peanut allergy is one of the most common causes of severe allergy attacks. For some people with peanut allergy, even tiny amounts of peanuts can cause a serious reaction that can even be life-threatening (anaphylaxis).

Peanut allergy has been increasing in children. Even if you or your child has had only a mild allergic reaction to peanuts, it's important to talk to your doctor. There is still a risk of a more serious future reaction.

Symptoms

An allergic response to peanuts usually occurs within minutes after exposure. Peanut allergy signs and symptoms can include:

  • Skin reactions, such as hives, redness or swelling
  • Itching or tingling in or around the mouth and throat
  • Digestive problems, such as diarrhea, stomach cramps, nausea or vomiting
  • Tightening of the throat
  • Shortness of breath or wheezing
  • Runny nose

Anaphylaxis: A life-threatening reaction

Peanut allergy is the most common cause of food-induced anaphylaxis, a medical emergency that requires treatment with an epinephrine (adrenaline) autoinjector (EpiPen, Auvi-Q, others) and a trip to the emergency room.

Anaphylaxis signs and symptoms can include:

  • Constriction of airways
  • Swelling of the throat that makes it difficult to breathe
  • A severe drop in blood pressure (shock)
  • Rapid pulse
  • Dizziness, lightheadedness or loss of consciousness

When to see a doctor

Talk to your doctor if you have had any signs or symptoms of peanut allergy.

Seek emergency treatment if you have a severe reaction to peanuts, especially if you have any signs or symptoms of anaphylaxis. Call 911 or your local emergency number if you or someone else displays severe dizziness, severe trouble breathing or loss of consciousness.

Causes

Peanut allergy occurs when your immune system mistakenly identifies peanut proteins as something harmful. Direct or indirect contact with peanuts causes your immune system to release symptom-causing chemicals into your bloodstream.

Exposure to peanuts can occur in various ways:

  • Direct contact. The most common cause of peanut allergy is eating peanuts or peanut-containing foods. Sometimes direct skin contact with peanuts can trigger an allergic reaction.
  • Cross-contact. This is the unintended introduction of peanuts into a product. It's generally the result of a food being exposed to peanuts during processing or handling.
  • Inhalation. An allergic reaction may occur if you inhale dust or aerosols containing peanuts, from a source such as peanut flour or peanut oil cooking spray.

Risk factors

It isn't clear why some people develop allergies while others don't. However, people with certain risk factors have a greater chance of developing peanut allergy.

Peanut allergy risk factors include:

  • Age. Food allergies are most common in children, especially toddlers and infants. As you grow older, your digestive system matures, and your body is less likely to react to food that triggers allergies.
  • Past allergy to peanuts. Some children with peanut allergy outgrow it. However, even if you seem to have outgrown peanut allergy, it may recur.
  • Other allergies. If you're already allergic to one food, you may be at increased risk of becoming allergic to another. Likewise, having another type of allergy, such as hay fever, increases your risk of having a food allergy.
  • Family members with allergies. You're at increased risk of peanut allergy if other allergies, especially other types of food allergies, are common in your family.
  • Atopic dermatitis. Some people with the skin condition atopic dermatitis (eczema) also have a food allergy.

Complications

Complications of peanut allergy can include anaphylaxis. Children and adults who have a severe peanut allergy are especially at risk of having this life-threatening reaction.

Prevention

According to recent studies, there is strong evidence that introducing at-risk babies to peanuts as early as 4 to 6 months of age may reduce their risk of developing food allergies by up to 80%. Babies at risk for peanut allergy include those with mild to severe eczema, egg allergy, or both. Before introducing your baby to peanuts, discuss the best approach with your child's doctor.

June 25, 2020
  1. Burks AW, et al. Middleton's Allergy: Principles and Practice. 9th ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed May 18, 2020.
  2. Wang J. Peanut, tree nut, and seed allergy: Management. https://www.uptodate.com/contents/search. Accessed May 18, 2020.
  3. Rich RR, et al. Clinical Immunology: Principles and Practice. 5th ed. Elsevier; 2019. https://www.clinicalkey.com. Accessed May 18, 2020.
  4. Anaphylaxis. American College of Allergy, Asthma and Immunology. https://acaai.org/allergies/anaphylaxis. Accessed May 18, 2020.
  5. Keet C, et al. Food allergy in children: Prevalence, natural history, and monitoring for resolution. https://www.uptodate.com/contents/search. Accessed May 18, 2020.
  6. FDA approves first drug for treatment of peanut allergy for children. U.S. Food and Drug Administration. https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-treatment-peanut-allergy-children. Accessed May 18, 2020.
  7. The current state of oral immunotherapy (OIT) for the treatment of food allergy. American Academy of Allergy, Asthma and Immunology. https://www.aaaai.org/conditions-and-treatments/library/allergy-library/oit. Accessed May 18, 2020.
  8. Epinephrine auto-injector. American College of Allergy, Asthma and Immunology. https://acaai.org/allergies/allergy-treatment/epinephrine-auto-injector. Accessed May 18, 2020.
  9. Peanut allergy. Food Allergy Research and Education. https://www.foodallergy.org/living-food-allergies/food-allergy-essentials/common-allergens/peanut. Accessed May 18, 2020.
  10. Sicherer SH. Food allergy in schools and camps. https://www.uptodate.com/contents/search. Accessed May 18, 2020.
  11. Addendum guidelines for the prevention of peanut allergy in the United States: Report of the NIAID-sponsored expert panel. National Institute of Allergy and Infectious Diseases. https://www.niaid.nih.gov/diseases-conditions/guidelines-clinicians-and-patients-food-allergy. Accessed May 26, 2020.

Related

Associated Procedures

Products & Services