Peanut Allergy

Peanut allergy prevalence has tripled in American children, from 0.4% in 1997 to 1.4% in 2008. Peanut allergy often presents by age 2 with 75% of allergic reactions occurring on the first exposure to peanuts. Twenty percent of people with peanut allergies can have life-threatening reactions termed anaphylaxis. This guide was created to help you understand what a peanut allergy is, how to recognize the symptoms, and how to prevent allergic reactions if you have a peanut allergy.

What causes allergies to foods such as peanuts?

A food allergy happens when your immune system inappropriately targets a particular food as a harmful substance. When a person has a peanut allergy, the body's immune system reacts to one or more of the proteins found in peanuts resulting in allergy symptoms. These proteins are found in both raw and cooked peanuts, as well as some peanut oils. Anyone can develop a peanut allergy, but it's more common in people who have food allergies, asthma, eczema, or hay fever (or a family history of these conditions).

Why do peanut allergies get special attention?

Peanuts and tree nuts are the foods most commonly associated with near-fatal and fatal allergic reactions. Every year, it is estimated 150 deaths are caused by allergic reactions to peanuts and nuts. Accidental and unintentional exposures often occur despite the best efforts of avoidance. Trace amounts of peanuts can cause reactions, although most objective symptoms are caused by the equivalent of one peanut kernel or more.

Because of the many ways a strongly allergic person can come into contact with peanuts, it takes careful planning to maintain a peanut-safe environment.

What are the most common symptoms of peanut allergy?

Common signs of an allergic reaction to peanuts, which can range from mild to severe, are:

• Hives/itchy rash
  
• Coughing/wheezing
  
• Runny nose/watery eyes
  
• Tingling of the lips/mouth
  
• Tightening of the throat
  
• Stomach pain/nausea/vomiting/diarrhea

What is anaphylaxis?

The most serious reaction to a peanut allergy is called anaphylaxis (an-uh-fa-lak-sis). Anaphylaxis is a life-threatening allergic reaction. Anaphylaxis happens suddenly and involves dangerous changes to your breathing, heart rate, and other body functions. Anaphylaxis also occurs when several different symptoms occur together, such as getting a rash and wheezing, or stomach pain and swelling of the throat. Anaphylaxis usually happens within seconds to minutes of exposure to an allergen and is life-threatening without emergency medical treatment.

If you or someone you know experiences anaphylaxis after coming into contact with a peanut product, use the EpiPen® injector and call 911 right away! Because anaphylaxis to peanuts is unpredictable and potentially life-threatening, you must always carry your EpiPen® with you.

How can I plan ahead?

If you have peanut allergy you should have a written treatment plan ready in case of an allergic reaction and make sure your teachers, camp counselors, friends (and others you may be with) know what to do in the case of an emergency. Anyone with peanut allergies should carry an auto injector device loaded with an emergency medication called epinephrine that can be used to treat anaphylaxis as soon as symptoms set in. This device is called an “EpiPen®” or Twinject®, and must be prescribed by a health care provider. Instructions for using an EpiPen® can be found here.

Have the EpiPen® or Twinject® with you at all times, it can save your life!

How do I know if a food has peanuts in it?

Certain foods (such as peanut butter, mixed nuts, and some candy bars) are obvious sources of peanuts, but some foods that contain trace amounts of peanuts aren't as easy to spot. Peanuts may be found in baked goods, crackers, sauces, pesto, Asian foods, veggie burgers, nougat, chocolate, ice cream, cereal, granola, Worcestershire sauce, and bouillon. Since 2006, it is a federal requirement that the Nutrition Facts Label on all packaged foods must list the eight most common food allergens: peanuts, tree nuts, milk, egg, wheat, soy, fish, and shellfish. You must always check that a food is safe by reviewing the ingredient list on the food label. Unfortunately, restaurant foods, bakery items, and foods prepared by other people don't have labels. Whenever you are eating at a restaurant, be sure to tell the wait staff that you have food allergies and that none of the entrees you order can have peanuts or nuts. Also be aware that accidental exposures often occur due to cross-contact, such as using the same knife to cut a peanut butter sandwich to cut your tuna fish sandwich, or using the same ice cream scoop that has been contaminated with pistachio or maple walnut ice cream for your plain vanilla ice cream. Avoid items that have unknown ingredients.

If you have an allergy to peanuts, you know that it can be scary when you come in contact with peanuts, peanut oil, or other peanut ingredients. Having a peanut-safe life is possible by learning what foods you can and cannot eat. This will help prevent mild symptoms to serious reactions such as anaphylaxis. Tell your friends, teachers, and others that you spend time with that you have peanut allergy, just in case you ever need their help.

What is the treatment for peanut allergy?

There is presently no cure for peanut allergy. Avoiding peanuts and foods that contain peanuts is the only way to prevent reactions. Most people with peanut allergy have the allergy for life, but 20% of young people do outgrow it. If some time has passed since your last allergic reaction, your doctor may repeat peanut allergy testing and if it's negative, he or she may suggest a food challenge. A food challenge is done at a hospital or doctor's office (NEVER at home), and involves the medically supervised administration of small and increasing amounts of peanuts while a health care provider watches for symptoms of an allergic reaction. If no symptoms appear, that person's peanut allergy has resolved and he or she can start eating peanuts again.

Will there ever be a cure for peanut allergy?

There are several promising areas of research that may eventually lead to definitive treatment of peanut allergy. These include vaccines, oral desensitization protocols, and special formulas of Chinese herbal medicines. These are currently undergoing trials and hopefully will be ready for use in the near future.

If you are allergic to peanuts and tree nuts, learn about preventive and avoidance measures, have an emergency action plan ready and always carry an Epipen®.

Websites

foodallergy.org

peanutfreeplanet.com

Books

The Peanut Allergy Answer Book 2nd Edition by Michael C. Young, MD
Fair Winds Press, 2006

Written by the CYWH Staff at Children's Hospital Boston

Updated: 7/12/2011

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