Nut Allergy

Medically Reviewed by Nayana Ambardekar, MD on September 17, 2022
3 min read

Nut allergies are when your body’s immune system overreacts to the proteins found in nuts. Your body treats them as a potential threat and tries to fight them off. This response is an allergic reaction.

Even a little bit that you swallow or inhale can bring it on. It’s easy to avoid the nuts themselves, but they’re also added to a lot of other foods, and you may not always be aware.

Signs of a nut allergy can include:

Call your doctor right away if you have any of these after eating any kind of nut.

Tiny proteins found in nuts aren’t affected by things like heat or acid, so they’re still intact after they’re processed, cooked, or even digested. Some people are sensitive to these intact proteins, and their bodies make antibodies to fight them.

The antibodies latch on to the proteins. This triggers your immune system to release a chemical called histamine. Histamine is actually what causes the symptoms of an allergic reaction.

Peanuts and tree nuts aren’t the same. But if you’re allergic to one, you may also need to avoid the other. Ask your doctor to be sure.

Tree nuts include:

  • Almonds
  • Brazil nuts
  • Cashews
  • Chestnuts
  • Filberts
  • Hazelnuts
  • Hickory nuts
  • Macadamia nuts
  • Pecans
  • Pistachios
  • Walnuts

You may find peanuts or tree nuts in things like these:

  • Baked goods: Cookies, candy, pastries, pie crusts, and others
  • Candy: Chocolate candy especially; also nougat and marzipan
  • Other sweets: Ice cream, frozen desserts, puddings, and hot chocolate
  • Cereals and granola
  • Trail mix
  • Chili and soups. Peanuts or peanut butter are sometimes used as thickeners.
  • Grain breads
  • High-energy bars
  • Honey
  • International foods. Nuts are common ingredients in African and Asian cooking (especially Thai and Indian foods), and in Mexican and Mediterranean foods.
  • Mortadella. This Italian ham may include pistachios.
  • Veggie burgers
  • Sauces. These may include barbeque sauce, hot sauce, pesto, gravy, mole sauce, glazes, or marinades.
  • Salads and salad dressing

Nix them when you cook, and look for them on food labels:

  • Nut butters: Almond, cashew, peanut, and others
  • Nut pastes. These include products like marzipan, almond paste, and nougat.
  • Nut oils. These include cold-pressed or expressed peanut oil, along with others.
  • Hydrolyzed plant or vegetable protein. These can have peanuts in them.
  • Peanut flour
  • Nut extracts, like almond extract

The best way to treat an allergy to nuts is to prevent a reaction by staying away from them. Read menus and food labels very carefully when eating out or shopping.

New studies looking for treatment of peanut allergies have found that peanut immunotherapy drops administered under the tongue are safe and effective as treatment for peanut allergy, even in children as young as 1. They were also found to help significantly desensitize the patients to peanuts.

If you accidentally eat something with nuts in it, watch for signs of a serious allergic reaction (anaphylaxis), like trouble breathing or swallowing, tightness in your chest, stomach pain, vomiting, or a feeling of doom. These reactions can be life-threatening and need medical attention right away. You should:

  • Lie down flat on your back.
  • If you have epinephrine, use it and repeat after 5 to 15 minutes if your symptoms haven’t gotten better.
  • Call 911 and get medical help.

If you have a nut allergy, carry two epinephrine auto-injectors (Auvi-Q, EpiPen, Symjepi) at all times, and know how to use them.

Children with serious peanut allergies may benefit from using the drug Palforzia, which can help lessen symptoms they’re exposed.


  • Ask your server. Foods that don't have peanuts or tree nuts in them can still get contaminated if they’re made in the same place or with the same equipment as food that has the nuts. It can also happen in restaurants that use lots of ingredients, and even in ice cream parlors if equipment, like scoops, are shared.
  • Check the label each time you buy a product. Food makers sometimes change the recipe.
  • Look outside the kitchen. Nuts can also be in lotions, shampoos, and pet food. Check labels before you buy or use them.