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Peanuts and tree nuts are some of the most common food allergens in the U.S. More than six million Americans of all ages are allergic to peanuts and nearly four million are allergic to tree nuts according to Food Allergy Research and Education. And those numbers have steadily continued to increase over the last few decades. 

Despite how common they are, the public often misunderstands food allergies including peanut and tree nut allergies, symptoms, and treatments. Here is what you really need to know. 

What is a nut allergy?

Peanut and tree nut allergies are serious food allergies. Once ingested, these substances can cause symptoms in those who are allergic within seconds, minutes, or hours.

“When you have a food allergy your immune system overreacts to something like a peanut or tree nut,” says Alissa McInerney, MD, a pediatric and adult allergist with Summit Health in New York City. “Even though it’s a benign substance, your body thinks it's a foreign invader that it needs to attack."

Peanut and tree nut allergies are different, and some people can be allergic to one or another or both. Some people are even allergic to a single type of tree nut and not others. Peanuts are legumes ­— related to peas and lentils — that grow on vines. It is important to note, however, that if you are allergic to peanuts it does not mean you will be allergic to all legumes. Tree nuts are a broader classification for edible nuts that grow on trees such as cashews, pistachio, hazelnut, walnut, almond, and pecans. 

“In the past, physicians would just tell patients to avoid them all,” Dr. McInerney says. “But now we can test more specifically to see exactly which type of tree nut patients are allergic to and even specific tests called component tests that can help distinguish a true anaphylactic allergy and a mild itching that can be seen in patients who are very allergic to pollen."

Nut allergy symptoms

The symptoms of nut allergies range from mild to severe. People may experience multiple symptoms at the same time. They include:

  • Hives, rash, itchy, and/or red skin
  • Tingling and swelling of the lips and/or mouth
  • Runny nose
  • Tightness in the throat
  • Shortness of breath and/or wheezing
  • Cramps, stomach pain, diarrhea, nausea, and/or vomiting
  • Rapid pulse
  • Drop in blood pressure
  • Dizziness, faintness, and/or loss of consciousness

Dr. McInerney says most reactions start off like seasonal allergies. But they can rapidly turn into anaphylaxis, which is a systemic and possibly life-threatening situation.

“Many people think anaphylaxis is simply having your throat closing up," she says. “That’s a common misconception. If you see severe reactions happening or with multiple body systems — such as hives and vomiting or swelling and trouble breathing — that's anaphylaxis."

Nut allergy treatments

Step one: avoidance. If you know you are allergic to peanuts or tree nuts, you will need to avoid eating foods that contain the allergen from your diet. Depending on the severity of your allergy, you may also need to stay away from foods that contain trace amounts of the allergen. Individuals with very serious allergies may also need to avoid contact with peanuts or tree nuts by sitting at a different table than someone eating a peanut butter sandwich or bag of almonds. This used to be the mainstay of treatment, but new therapies have been developed, including oral immunotherapy, where a patient eats a small amount of the allergen under the strict guidance of the allergist.

Step two: antihistamines. To counter minor symptoms of nut allergies, like a runny nose or itching, an over-the-counter antihistamine is the place to start, says Dr. McInerney. However, she warns, “Anaphylaxis doesn't get better on its own. It progresses. In general, anaphylaxis can only be treated with epinephrine.”

Step three: epinephrine auto-injector, also commonly known as an EpiPen®. An epinephrine auto-injector is a medical device that is used to inject the hormone epinephrine/adrenaline in emergency situations when an individual is having a life-threatening anaphylactic reaction to peanuts, tree nuts, or another allergen. An epinephrine auto-injector is easy to use. You or a family member can administer an epinephrine auto-injector into your thigh without ever seeing a needle. 

“Epinephrine treats your symptoms and reverses them," Dr. McInerney says. “It will work almost immediately." This is especially helpful when the anaphylactic reaction involves throat tightening and closure, blood pressure problems — which can lead to loss of consciousness — and uncontrollable, painful digestive symptoms.

Developed to pierce army uniforms, an epinephrine auto-injector can easily penetrate anything you may be wearing at the time, even thick jeans. After it's used, patients return them to their allergists or doctors and receive prescriptions for new ones.

“An epinephrine auto-injector, which you may also have heard called an EpiPen®, lasts for a year, so you can keep them with you for that amount of time,” Dr. McInerney says. “I advise patients to have two packs with them for that rare occasion when they could use a second one if symptoms don’t improve with the first injection."

When to use an epinephrine auto-injectors

Dr. McInerney believes epinephrine auto-injectors are not used enough. People also tend to wait too long to give the injection. Whether it's because of the expense or the uncertainty, allergy sufferers often hesitate to inject themselves and wind up in the emergency room instead.

During an episode of anaphylaxis, it is critical that the epinephrine auto-injectors be administered within 30 minutes of when symptoms begin. Her rule of thumb: If you have symptoms and are questioning whether you should use the EpiPen, the answer is yes. 

“The main downside is it makes your heart race as a side effect," she continues. “But if you have severe reactions to nuts or anything else, you really need to have an epinephrine auto-injector and discuss with your allergist how and when to use it.”

Food intolerance

There can be various other reactions to food that are not caused by allergies, such as bloating, diarrhea, and abdominal discomfort. Often management is different for intolerance than for allergies. If you are not sure of the cause of your symptoms for primary care provider can help you reach the correct diagnosis or refer you to the appropriate specialist to get the answer. 

If you suspect you may have a food allergy, make an appointment with an allergist at Summit Health. Our team can help identify what you are allergic to and develop a treatment plan to help control your symptoms and keep you safe.