Peanut Allergy: Symptoms, Reaction, Tests & Treatment

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Peanut allergies happen when your immune system tries to protect you from a protein in peanuts that it mistakenly thinks is harmful. Peanut allergies can cause hives, airway swelling, difficulty breathing, vomiting and dangerously low blood pressure. Go to the ER or call 911 if you have severe symptoms after eating peanuts.

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Peanut allergies happen when your body mistakes peanut protein for something harmful. Your immune system responds by causing an allergic reaction, which could include hives, vomiting and swelling. Peanut allergies are the most common food-related cause of anaphylaxis, which can lead to swelling in your airways or a severe drop in blood pressure. Call 911 (or your local emergency service number) or get to an emergency room immediately if you have face, mouth or throat swelling, difficulty breathing or swallowing, or feel faint.

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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

No. Peanut allergies aren’t the same as tree nut allergies (which include cashews, walnuts, hazelnuts, pecans, pistachios and Brazil nuts). Peanuts are legumes and grow in the ground. But some people are allergic to peanuts and some or all tree nuts.

Symptoms of peanut allergies, including anaphylaxis, can include sudden onset of:

• Hives or skin rash
• Itchy skin
• Flushing
• Vomiting
• Diarrhea
• Swelling of your face, lips, mouth or tongue
• Itchy mouth and throat
• Hoarse voice
• Difficulty swallowing
• Wheezing
• Shortness of breath or difficulty breathing
• Abdominal pain
• Lightheadedness or loss of consciousness
• Runny nose
• Sneezing

Symptoms of peanut allergies can be severe, even if you’ve only had a mild reaction in the past. Call 911 or go to the ER at the first sign of severe symptoms.

In addition to the symptoms above, if a baby or young child is having a reaction to peanuts, they might have a hoarse cry, noisy breathing and/or hiccups. You might also notice they’re:

• Rubbing their eyes
• Scratching at their ears
• Pulling on their tongue
• Arching their back

If you have a peanut allergy, your symptoms will usually start within two hours of eating peanuts.

When you have a peanut allergy, your immune system mistakenly identifies a protein in peanuts as something harmful. When you eat peanuts or something that contains peanuts, your body takes steps to protect you from the protein and flush it out of your system. These steps cause your symptoms, which can sometimes be life-threatening.

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You might be at a higher risk for a peanut allergy if:

• You have other food allergies, especially an egg allergy
• You have allergies to pollen, pets or substances other than food
• You have eczema or asthma
• One or both of your biological parents has a peanut allergy or other allergies, asthma or eczema

The most serious complication of peanut allergies is anaphylaxis, or swelling in multiple body systems. Anaphylaxis can cause uncontrolled vomiting, difficulty breathing and a severe drop in blood pressure (anaphylactic shock). Severe anaphylaxis can be fatal.

Healthcare providers diagnose peanut allergies by talking to you about your symptoms and performing allergy testing. Your provider may ask you:

• What symptoms you experienced
• What you ate and how much of it you ate
• When the symptoms started
• What you did to relieve the symptoms
• How long the symptoms lasted
• Whether you have other known allergies (to food, pollen, dust, pets, etc.)
• Whether you have eczema or asthma
• Whether anyone else in your family has allergies, asthma or eczema

Testing for peanut allergies might include:

• Allergy skin test. A provider pricks your skin with tiny amounts of allergens (including peanut protein) to see if you develop a reaction.
• Allergy blood test. A provider tests your blood for IgE antibodies to allergens. High levels of antibodies to peanut protein can indicate an allergy to peanuts depending on your history.
• Food challenge test. Under the supervision of your provider, you’ll eat small, increasing amounts of peanut protein or peanut butter to see if you have a reaction.

The best way to manage peanut allergies is to avoid peanuts and food containing peanuts. But there are a few treatment options that might reduce your risk of having an allergic reaction if you’re exposed to peanuts. These include injections, oral immunotherapy and sublingual immunotherapy programs.

You should also keep emergency medications, like epinephrine, on hand in case you accidentally eat something containing peanuts.

Your provider gives you omalizumab (Xolair®) injections once every two to four weeks (or your provider can train you to do it yourself). It can reduce your risk of having a reaction if you’re accidentally exposed to peanuts. You still need to avoid peanuts and foods containing peanuts if you’re using omalizumab.

Oral immunotherapy (OIT) is a program that can help you or your child build a tolerance to peanuts. Your provider gives you increasing doses of peanut protein over several months. This might be given in the form of peanut butter or peanut allergen powder (Palforzia®).

The goal of OIT is to get to a point where you won’t have a reaction if you’re accidentally exposed to small amounts of peanuts (called “bite proof”). Some people can freely eat peanuts after OIT. For safety, a healthcare provider supervises and determines dosing for OIT.

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Sublingual immunotherapy (SLIT) works like OIT: You’re exposed to a small amount of peanut protein every day to develop tolerance to it. The difference with SLIT is that you put a liquid containing peanut protein under your tongue and let it dissolve. SLIT must be supervised by a healthcare provider for safety.

If you’re accidentally exposed to peanuts and have an allergic reaction, your provider might give you or recommend you take or carry:

• An epinephrine auto-injector (EpiPen® or Auvi-Q®) to use at the first signs of a severe allergic reaction
• Corticosteroids, which are steroids to reduce inflammation
• Antihistamines to help stop or slow down allergic reactions (but providers don’t prescribe them to prevent reactions from peanut allergies)

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If you or your child have a peanut allergy, you’ll have to develop habits that help avoid accidental exposure. This means reading labels on packaged foods, asking questions at restaurants and keeping an eye out for reactions when eating new foods.

An allergist can talk to you about available treatment options and what to do if you have a reaction. If you’re undergoing treatment to help you build tolerance to peanuts, your provider may test you periodically to see if your IgE antibody numbers are improving.

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Allergic reactions are unpredictable and may become more severe with each additional exposure. There’s no way to test for how severe your reaction to peanuts might be without eating them. So, even if you’ve only had a minor reaction to peanuts in the past, you still need to be cautious in the future.

Sometimes. About 20% (or 1 in 5) kids outgrow peanut allergies. Out of kids who outgrow the allergy, most do so by age 8.

While there’s no specific way to prevent peanut allergies, some strategies to reduce your child’s risk include:

• Eating peanuts regularly if you’re breastfeeding (as long as you’re not allergic to them yourself)
• Asking your baby’s healthcare provider when and how to introduce new foods (they may recommend introducing your child to common allergens earlier than usual or under the supervision of a provider, depending on your child’s other health conditions)
• Making sure they eat foods containing peanuts on a regular basis if you’ve safely introduced your child to peanuts and know they aren’t allergic (this might reduce their risk of developing an allergy later on)

Some common foods that contain peanuts or might be contaminated with peanuts include:

• Peanut butter
• Chocolate candy
• Baked goods
• Trail mix
• Granola or energy bars
• Sauces, including mole and enchilada sauce
• Nut products
• Almond or hazelnut paste (nougat, marzipan)
• Chili
• Some types of Asian cuisine, including egg rolls, sauces, and noodle and chicken preparations
• Meat substitutes
• Hydrolyzed plant or vegetable protein
• Lupine (people with peanut allergies often have reactions to lupine, too)

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This isn’t a comprehensive list. Always check any food to understand if it’s safe before eating.

Here are some ways to help prevent accidental exposure to peanuts:

• Check the ingredient labels on premade foods. In the U.S., the label must state if a product contains or could’ve come in contact with peanuts. Phrases to look for include “may contain,” “made on shared equipment” and “manufactured in a facility that also processes peanuts.”
• Double-check labels when you buy food, when you put it away and before you eat it.
• Remember that things like birdseed might also contain or come in contact with peanuts. Read labels and wash your hands after handling it.
• Start talking to your child early about how to manage their peanut allergy, like not sharing food if they don’t know if it’s safe to eat.
• Be cautious at restaurants. Ask about whether the food contains or has come in contact with peanuts — but remember that they might not be able to make any guarantees. Restaurants don’t have to note allergens in their foods.
• If you go out for ice cream, ask if they can use a different, clean scoop (that hasn’t been used in other ice creams) when making yours.
• Let anyone who’s around your child know about their allergy and what foods are safe for them to eat.
• Talk to your child’s school or daycare about their allergy. Understand what plans they have in place to avoid accidental exposure. Some classrooms are nut-free or nut-sensitive.
• Ask your healthcare provider if you have any questions about what you can and can’t eat.

Here’s how you can be prepared in case of an allergic reaction:

• Always carry an epinephrine auto-injector with you. Ask your provider to show you exactly how to use it.
• Make sure your child’s school or daycare has an allergy action plan (Food Allergy & Anaphylaxis Emergency Care Plan) from your child’s provider on file. This details what to do if your child has an allergic reaction.
• Provide your child’s school or daycare with an epinephrine pen and any other medications your child might need.

If you think you or your child has a peanut allergy, talk to a healthcare provider (and avoid peanuts and peanut products until you do). They can refer you to a specialist and guide you on next steps.

Go to the ER or call 911 if you experience:

• Swelling of your face, lips, tongue or throat
• Difficulty breathing
• Chest tightness
• Hives all over your body
• Tingling hands, feet or lips
• Feeling weak, dizzy or faint
• Feeling of impending doom

It might be helpful to ask your healthcare provider:

• Are there any treatment options available?
• What should I do if I have an allergic reaction or am accidentally exposed?
• What are some strategies to avoid accidental exposure?
• How do I use this medication?
• When do I need epinephrine?
• Can you give me a copy of an allergy action plan?

When you or your child is first diagnosed with a peanut allergy, you might start seeing peanuts everywhere — on labels and in a long list of foods to avoid. It’s true that you’ll probably always need to check labels and be cautious about what you or your child eats. But as this becomes second nature, it may start to feel easier to manage.

While there’s never a good time to have a peanut allergy, there are more options than ever for people who have to be extra cautious about what’s in their food. And new treatments give hope for less worry in every bite.

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Cleveland Clinic’s health articles are based on evidence-backed information and review by medical professionals to ensure accuracy, reliability and up-to-date clinical standards.

Cleveland Clinic’s health articles are based on evidence-backed information and review by medical professionals to ensure accuracy, reliability and up-to-date clinical standards.

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When you have a food allergy, you might worry a lot about what to eat so you don’t have a reaction. Cleveland Clinic can ease your fears and treat your allergies.

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