Peanut allergy occurs when your immune system develops antibodies to the protein in peanuts, because your body believes that peanuts are a harmful substance. The antibodies signal the immune system to release chemicals, such as histamine, into your bloodstream. This can adversely affect the skin, eyes, nose, airways, intestinal tract, lungs, and blood vessels.
Three different forms of exposure can lead to an allergic reaction:
- Direct contact—this can result from either eating peanuts or sometimes from touching peanuts
- Cross contact—this can result from ingesting a food that has come in contact with peanut protein during processing or food handling
- Inhalation—this can result from inhaling dust or aerosol products, such as peanut flour or cooking sprays that contain peanut oil
The following individuals are at greatest risk of developing peanut allergy:
- People with have a family member with food allergies
- Children who live in urban areas, rather than rural settings (more likely to develop food allergies)
Peanut allergy tests
The following tests are used to diagnose peanut allergy:
- Skin prick test—the skin is pricked and exposed to small amounts of peanut protein to see if a skin response occurs
- Blood test—levels of antibodies in your blood (known as immunoglobulin E antibodies) are measured to determine your immune system’s response to peanuts
Symptoms of peanut allergy
The symptoms of peanut allergy are similar to the symptoms of any other food allergy. However, the difference is their severity. Peanut allergy is the most common cause of food-allergy related death. Keep in mind that only 150 people die annually of all food allergies combined in the United States.
Children often outgrow allergies to eggs or milk, but it is rare for someone to outgrow a peanut allergy. Roughly one in five children eventually will recover from their peanut allergy, but the allergy may recur at any time.
Sufferers of peanut allergy can exhibit different symptoms and different levels of severity in their reactions. Common symptoms of food allergy include:
- Hives and other skin rashes
- Itching or tingling of the mouth and throat
- Gastrointestinal symptoms, including nausea, vomiting, stomach cramping, and diarrhea
- Chest tightness
- Shortness of breathing or wheezing
- Runny or stuffy nose
- Anaphylaxis,* can include:
- Facial swelling
- Sudden and rapid drop in blood pressure
- Rapid pulse
- Dizziness and lightheadedness
*If not treated immediately, a person in anaphylactic shock may die.
Treatment of peanut allergy
No treatment for peanut allergy exists, other than the avoidance of any and all peanut-containing products. If a person with an allergy accidentally comes in contact with peanuts, different treatments are available. A person in anaphylactic shock must receive epinephrine and then go to the emergency room; if your doctor feels that you are at risk, you should carry injectable epinephrine with you at all times. Antihistamines often are useful for people with mild allergic reactions.
Foods that may contain peanuts
Some foods that you would not expect to contain peanuts do. The only way to make sure that you do no ingest peanut-containing products is to carefully read the ingredient list on all food items before eating them. All foods must carry a warning if they contain peanuts or were produced in a factory that also processed peanut-containing foods.
The following foods are very likely to contain peanuts:
- Ground or mixed nuts
- Baked goods
- Ice cream and other frozen desserts
- Energy and protein bars
- Cereals and granola
- Grain breads
- Salad dressings
- African, Chinese, Indonesian, Mexican, Thai, and Vietnamese foods
References and recommended readings
AllegicChild.com™. Peanut allergy. Available at: http://www.allergicchild.com/peanut_allergy.htm. Accessed March 28, 2010.
Mayo Clinic. Peanut allergy. Available at: http://www.mayoclinic.com/health/peanut-allergy/DS00710. Accessed March 28, 2010.
PeanutAllergy.com. Peanut free food. Available at: http://www.peanutallergy.com/content/articles/foods/food-articles. Accessed March 28, 2010.
WebMD. Allergies Health Center: peanut allergy—overview. Available at: http://www.webmd.com/allergies/tc/peanut-allergy-overview. Accessed March 28, 2010.
Review Date 5/10