Nuts are a top food allergen in the United States. Taking steps to avoid them and knowing what to do if you’re exposed can protect your health.

An estimated 20 million people in the United States have food allergies. Nut allergy is one of the most common types of food allergies in both children and adults — some of whom may experience serious, life threatening reactions when exposed to nuts.

So if you have a nut allergy, it’s important to educate yourself, take precautions to avoid exposure, and know what to do if you experience symptoms.

Simply put, a nut allergy is when you experience symptoms of an allergic reaction after eating or being exposed to nuts.

The reaction typically occurs within minutes of exposure. But for some, the reaction may occur up to 6 hours later.

Symptoms of a nut allergy can range from mild to severe. For some, exposure to even trace amounts of nuts can be life threatening.

Skin reactions

Mild skin reactions of nut allergies often include:

Antihistamines such as diphenhydramine (Benadryl) or loratadine (Claritin) can help relieve rashes and hives. Cold, wet compresses can also help soothe irritated skin.

Symptoms affecting the eye, nose, and throat

Allergies often affect the upper respiratory tract. Common symptoms include:

  • stuffy or runny nose
  • sneezing
  • sore throat
  • itching or watery eyes

Antihistamines can also help relieve runny nose and irritated eyes. If the runny nose persists, try combining it with a decongestant such as pseudoephedrine (Sudafed).

Digestive distress

Many food allergies cause digestive problems as the allergenic proteins make their way through the stomach and intestines. Digestive reactions usually take a few hours to occur after eating nuts. It’s common to feel:

  • nausea
  • stomach cramps

If the allergic reaction is severe enough, you might experience:

  • vomiting
  • diarrhea

Eosinophilic esophagitis

Also known as EoE, this disorder of the esophagus is a possible complication of nut allergies.

Symptoms may include:

  • difficulty swallowing
  • chest pain
  • vomiting

Treatment of EoE will depend on which factors are causing it. If nut allergies are to blame, your doctor will advise you to eliminate nuts — and potentially other common food allergens — from your diet.

Difficulty breathing

Due to the swelling caused by the allergic reaction, the airways can become constricted or close completely. Shortness of breath can turn into allergic asthma, a condition in which the airways seize and restrict airflow.

If you experience difficulty breathing, seek medical care to determine the underlying cause and get proper treatment.

Anaphylaxis

Anaphylaxis is a severe and potentially life threatening allergic reaction. Some, but not all, cases of anaphylaxis may cause difficulty breathing due to throat swelling.

Anaphylaxis can also cause other symptoms, including:

People whose nut allergy is severe enough to develop anaphylaxis should always carry an intramuscular injection of epinephrine, such as an EpiPen.

An injection of epinephrine, also called adrenaline, causes the airways to reopen, allowing you to breathe again. It also increases low blood pressure and decreases the body’s release of histamine, the chemical in the body that’s responsible for the allergic reaction

When someone is allergic to nuts, their immune system mistakenly identifies the nuts as a harmful substance. It learns to recognize and react to these substances (allergens).

So when you’re exposed to the allergen, the body treats it as a threat. The immune system launches an attack by releasing chemicals such as histamine. This is what causes allergy symptoms.

And it’s possible to be allergic to more than one type of nut.

Types of nuts

Nuts, also known as tree nuts, come in different varieties. They include:

Although peanuts have the word “nuts” in their name, they aren’t nuts. Peanuts are legumes and, unlike tree nuts, grow underground. Although peanuts are not tree nuts, people with a peanut allergy have a similar allergic reaction as those with a tree nut allergy.

If you have one tree nut allergy, it’s highly likely that you’re allergic to other tree nuts as well. However, only 30% of people who are allergic to peanuts are also allergic to tree nuts.

Take care when eating food that might contain the nut you’re allergic to.

Peanuts can be found in beer nuts, peanut butter, and peanut oil. They’re also commonly used in Asian, African, and Mexican cuisine.

Other foods that may contain peanuts include:

  • baked goods
  • chocolate candy and sweets
  • chili
  • egg rolls
  • nougat
  • mole sauce
  • salad dressings
  • vegetarian meat substitutes
  • glazes
  • marinades

Tree nuts might be found in:

  • pesto
  • nut extract or nut oils
  • cereals
  • crackers
  • cookies
  • chocolate candy
  • energy bars
  • flavored coffees
  • frozen desserts
  • marinades
  • certain cold cuts, such as mortadella

Some alcoholic drinks may contain nut flavorings, and the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA) doesn’t require the manufacturer to list them on the label.

A diagnosis is essential to treating allergies. If someone suspects that they have allergies, they should be evaluated by an allergist.

An allergist can run a series of tests to find out what you’re allergic to. They can give you antihistamines to control allergy symptoms and an epinephrine injector in case you’re at risk for anaphylaxis.

Treating nut allergies often involves a mix of taking steps to prevent exposure and knowing when to take action and get treatment. That may include:

  • avoiding all tree nuts and peanuts, as well as products that contain them and products that have undergone processing in the same facilities as these foods
  • recognizing nut allergy symptoms and taking prompt action if they develop
  • taking antihistamines to address mild symptoms, such as itching or swelling, if they arise
  • carrying an epinephrine injector if you have a severe allergy so that you can treat anaphylaxis immediately if needed
  • working with your doctor on food immunotherapy, where you’re intentionally exposed to increasing doses of the allergen over time to train your immune system to tolerate it
  • informing loved ones about your allergy (including teachers, caregivers, and coaches of children with nut allergies)
  • asking about medications like Palforzia to help manage peanut allergies in children

After you’ve been diagnosed, education is the key to managing your nut allergy.

Carefully reading all food labels and learning about cross-contamination risk is imperative. As a requirement of the federal FALCPA, all prepackaged food in the United States that use nuts as an ingredient must list the type of nut on the label.

For now, there are no rules requiring food manufacturers to list if their food has been contaminated with, or processed on, the same equipment as other foods containing nuts.

“Nut-proofing” a household can reduce the risk of accidental exposure and onset of nut allergy symptoms. Cleaning surfaces with cleaning sprays or sanitizing wipes can remove peanut residue. Washing the hands with running water and soap after handling nuts can also reduce the risk of contamination.

Nuts are one of the top food allergens. If exposed, reactions can range from mild to life threatening.

Taking steps to avoid exposure to nuts is the best way to prevent an allergic reaction. However, treatments are available to treat mild symptoms and prevent severe life threatening reactions if exposure to nuts does occur.