What Are the Symptoms of a Nut Allergy?

Medically reviewed by Xixi Luo, MD on August 29, 2017Written by Healthline Editorial Team

Allergies, in a nutshell

Over 50 million Americans have allergies, according to the Centers for Disease Control and Prevention. Nut allergy is one of the most common types of food allergy in both children and adults.

Nut allergies tend to last a lifetime, although about 14 percent of children with a tree nut allergy, and 20 percent of children with a peanut allergy, eventually outgrow them. Younger siblings of children with a nut allergy are at higher risk of being allergic to nuts as well.

Types of nuts

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

Although peanuts have the word nut 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 about 25 to 40 percent of people are allergic to both peanuts and tree nuts, according to Food Allergy Research & Education (FARE).

Allergies and the immune system

When someone is allergic to nuts, their immune system mistakenly identifies nuts as a harmful substance. The immune system reacts to these substances, or allergens. The first time someone is exposed to a nut allergen, they usually don’t have any symptoms. Their immune system, however, has recognized the allergen as a threat and gets ready to fight the allergen the next time it enters the body.

When the allergen enters the body again, the immune system launches an attack by releasing chemicals such as histamine. The release of histamine is what causes allergy symptoms. Get a more detailed look at allergies.

Skin reactions

Mild skin reactions of nut allergies often include:

Antihistamines such as diphenhydramine (Benadryl) or loratidine (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:

Antihistamines can also help relieve runny nose and irritated eyes. If the runny nose persists, try combining 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:

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

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. It can also cause anaphylaxis, a condition in which the throat swells, causing difficulty breathing.

These symptoms fall on a spectrum. You could develop one of the symptoms, or you might develop them all.

Anaphylaxis

Anaphylaxis is the most severe and dangerous form of allergic reaction. In anaphylaxis, the throat and airways swell and become blocked. This makes it extremely difficult, sometimes even impossible, to breathe. It 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.

Getting diagnosed

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 EpiPen in case you’re at risk for anaphylaxis. Find out everything you need to know about allergy testing.

Check your food labels

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 Food Allergen Labeling and Consumer Protection Act of 2004 (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.

Suspicious foods

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, which FALCPA doesn’t require the manufacturer to list on the label.

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