Peanut Allergy

A peanut allergy is an abnormal response of the body to the proteins found in peanuts. It’s a type of food allergy that is becoming more common in children.

Peanuts are not actually a type of tree nut but are legumes in the same family as soybeans, peas, and lentils. Because legumes and tree nuts have similar proteins, children who are allergic to peanuts may also be allergic to tree nuts such as pecans, pistachios, and walnuts.

Children who are allergic to peanuts should avoid foods that contain:

• Peanuts
• Peanut butter
• Peanut flour
• Peanut oil (highly refined peanut oil may be safe for some people; ask your allergist)
• Ground nuts
• Mixed nuts

Peanuts or peanut proteins may also be found in:

• Asian and Mexican foods, and other ethnic foods where peanuts are commonly used
• Baked goods and candy
• Some sauces and marinades
• Chili
• Crackers
• Ice cream
• Packaged food

If you’re not sure if a packaged food contains peanuts, read the label. Under the Food Allergen Labeling and Consumer Protection Act of 2004, food products sold in the U.S. that contain peanuts must list peanuts in the ingredient list.

Symptoms can range from mild to life-threatening. They can include:

• Itchy skin
• Hives
• A tingling feeling in the mouth or throat
• A runny nose or congestion
• Nausea
• Anaphylaxis: a life-threatening reaction that can cause trouble breathing, swelling in the throat, fainting, dizziness, and a drop in blood pressure

It is not known why some people develop peanut allergies. In some cases, food allergies can run in families.

A peanut allergy may be diagnosed using a skin test or a blood test. Your child’s doctor may also ask you to keep a food journal. If it’s not clear what food may be causing your child’s symptoms, the doctor may suggest an elimination diet, cutting out the suspected foods one at a time.

There is currently no treatment to prevent a peanut allergy. In some cases, children outgrow it over time.

The medication epinephrine (adrenaline) is used to treat anaphylaxis. Children at risk for anaphylaxis should be prescribed an auto-injector of epinephrine and carry two doses with them at all times. Your child should use epinephrine right away if he or she has any severe symptoms, such as shortness of breath, hives, tightness in the throat, or trouble breathing or swallowing.

At the Boston Children’s Hospital Food Allergy Program, our experts treat all types of food allergies, addressing medical, dietary, social, and psychological concerns. The clinic is hosted by Boston Children's Division of Allergy and Immunology, the largest provider of pediatric allergy services in the region.