Nut and Peanut Allergy in Babies: Signs and Causes

Written by Taylor Cossairt, medically checked by child nutritionist

The most common food allergy in kids (18 years or younger) is peanuts, affecting about 2% of all children. It’s also the second-most common food allergy among adults (19 years and older). And about 20% of children who are allergic to peanuts carry the allergy with them into adulthood.

It might seem easy enough to avoid peanuts, but they’re a common food ingredient. Think foods like:

  • Baked goods
  • Egg rolls
  • Granola
  • Peanut butter
  • And more

Children who have peanut allergies are actually allergic to proteins found in peanuts. When your child eats a peanut, those proteins bind to a type of immune system antibody. And your child’s body thinks it has to attack those proteins.

As the body fights off peanuts, physical symptoms start showing up (like wheezing, rashes, and so on). Further, peanut allergies are scary because in some cases, they’re life-threatening. This means parents and caregivers have to know what to look for and which foods to avoid.

Symptoms and Signs of a Peanut Allergy in Babies

Peanut allergy symptoms range from mild to severe. And they can show up slowly (in a few hours) or suddenly (in a few seconds). Here are the most common symptoms of an allergic reaction to peanuts, and what you can look out for:

Mild peanut allergy symptoms

  • Skin rash
  • Hives around the mouth or face
  • Itchy mouth
  • Runny nose and congestion
  • Nausea

Severe peanut allergy symptoms

  • Swelling around the lips, tongue, or face
  • Severe drooling
  • Severe itching around the mouth, ears, or face
  • Vomiting
  • Hives or welts all over the body
  • Wheezing and/or difficulty breathing
  • Fatigue or lethargy
  • Change in skin color (they’re looking pale, gray, or blue)
  • Anaphylaxis (rare)

Keep in mind that sometimes young children don’t have the words yet to describe what they’re feeling. Here are some key phrases to listen for:

  • My tongue feels weird
  • My mouth is itchy
  • Something’s in my throat
  • My mouth feels funny

You may also notice your child pulling or scratching their ears or mouth. And if their breathing stops or slows, call 911 immediately. They may be experiencing anaphylaxis (a severe allergic reaction).

Nut Allergies vs. Peanut Allergies in Babies

Surprisingly, tree nut allergies and peanut allergies aren’t the same things. Although, 40% of children who are allergic to tree nuts are also allergic to peanuts. And both tree nut allergies and peanut allergies “count” as a nut allergy. This is because peanuts and tree nuts have similar biological structures.

So how can parents know if their baby is allergic to nuts? And how do they know which type of nut their child is allergic to?

Here is what you need to know to get started:

Tree Nuts

  • Almonds, cashews, coconuts, pecans, pistachios, walnuts, and others
  • Grow on trees


  • Just peanuts
  • Grow underground

Although peanut allergies are more common, it’s tough to know what your child is allergic to. Whether your child is allergic to tree nuts or peanuts, the symptoms are identical. This is why it’s best to consult a medical professional and get them tested.

When you should Call 911 for a Peanut Allergy

If you suspect your child is reacting to peanuts, it’s best to consult with your doctor. And in some rare cases, symptoms may be severe enough to warrant calling 911. Here’s what to look out for:

  • Difficulty breathing
  • No breathing
  • Severe swelling of the throat, mouth, or face
  • Severe abdominal cramping and pain
  • A sudden drop in blood pressure
  • Fast pulse
  • Loss of consciousness
  • Severe symptoms involving two or more parts of the body. For example, shallow breathing and diarrhea

If your child has any of these symptoms, call 911 right away. Your child may be suffering from anaphylaxis. It’s a life-threatening allergic response. And the sooner your child gets to the hospital, the better. While you wait for medical attention, here’s what you can do:

  • Administer an auto-injector (also known as an EpiPen®)
  • Administer over-the-counter (OTC) antihistamines like Benadryl
  • Comfort your child and track their symptoms


Remember: Never hesitate to consult with a medical professional. Always seek emergency care if needed.

Even if their symptoms go away after a couple of minutes, go to the doctor anyway. Sometimes a “second wave” of symptoms may show up.

Top Foods to Avoid if your Baby has a Peanut Allergy

The best way to manage your child's peanut allergies is through diet monitoring. This is why it’s important to:

  • Read food labels
  • Check ingredients
  • Stay vigilant

After all, a wide variety of foods contain peanuts. Here’s a list of common ingredients to look out for:

Foods To Avoid: Peanut Allergy

  • Arachis oil
  • Artificial nuts
  • Baked goods containing peanuts
  • Beer nuts
  • Cold-pressed peanut oil
  • Egg rolls
  • Expelled peanut oil
  • Extruded peanut oil
  • Granola
  • Groundnuts
  • Lupin or lupine
  • Mandelonas
  • Mixed nuts
  • Monkey nuts
  • Nut meat or nut meal
  • Nut pieces
  • Peanut butter
  • Peanut flour
  • Peanut protein hydrolysate
  • Sauces like chili sauce, hot sauce, mole sauce, and some salad dressings
  • Some alternative nut butters
  • Some vegetarian or gluten-free food substitutes
  • Trail mix

And unless your child is allergic to tree nuts or anything listed below, they should be able to eat these foods:

Misleading Foods That Might Be OK

  • Butternut squash
  • Chestnuts
  • Coconuts
  • Nutmeg
  • Pine nuts
  • Water chestnuts

Keep in mind that the peanut allergy list above is only a guideline. It should in no way replace a medical professional’s advice. Talk with your doctor about what your child can, and can’t, eat.

Peanut Allergy Prevention and Treatment

Peanut allergies are common and in some cases, they’re serious. The best way to manage your child’s allergy is to prevent them from eating peanuts (or any foods made with peanuts).

But of course, it’s still possible your child may eat peanuts on occasion by accident. This is why it’s important you talk with your kid’s doctor and allergist to come up with a treatment plan. Here are some common peanut allergy treatment examples:

Allergy action plans
  • Peanut allergy action plans describe your child’s allergy and what to do in case of a reaction
  • Include a list of symptoms, triggers, and contact information
  • Make sure you outline emergency care instructions
  • For example, your child’s action plan may instruct a caretaker to use an auto-injector
  • Have your child’s doctor and/or allergist review the action plan
  • Share the action plan with friends, family members, teachers, and so on
  • If your child has an auto-injector, make sure you carry it at all times
  • You may administer OTC antihistamines or other medications as directed by a doctor
  • Talk with a medical professional to find out which medications are safe for your child
Food label monitoring
  • Check food labels for peanuts or hidden peanut ingredients like Arachis oil. Read a list of other foods to avoid here
  • Avoid cross-contamination in restaurants or commercially-prepared foods. Look for text like “may contain peanuts”
  • The EU, UK, and US require most food manufacturers to include a list of common allergens (like peanuts) on food labels
  • Look for ingredients that are underlined, bolded, or highlighted to identify allergens quickly

Cross-contamination and peanut allergies

Peanuts are a common food ingredient. You’re likely to find them in baked goods like brownies with nuts, chocolate bars, or egg rolls. But you can also find peanuts in foods that don’t usually contain them.

For example, a chocolate bar that’s made without peanuts might put your child at risk for a reaction. This is because the chocolate bar could have been made in a facility that also makes bars with peanuts. And it’s also why eating out and visiting restaurants is risky.

If surfaces and utensils aren’t cleaned thoroughly, peanuts may transfer between foods. This is called cross-contamination and it can be dangerous.

Check food labels for “manufactured in a facility that also processes peanuts." This helps reduce your child’s risk of a cross-contamination reaction.

How to Diagnose Peanut Allergies in Babies

If you suspect your child has a peanut allergy, talk with a doctor or allergist. They’ll be able to diagnose your child so you can properly manage their symptoms. Here are a couple of ways medical professionals may diagnose a peanut allergy:

Skin test

  • A medical professional applies a peanut allergen to your child’s skin
  • Then, they administer small pricks along the skin
  • This exposes your child to peanuts
  • If a reaction occurs, it’s likely they have an allergy

Blood test

Elimination diet

Peanut allergy food journal

Explore Other Most Common Foods Causing Allergies in Babies

FAQ: Everything you need to Know about Baby Peanut Allergies

Is a nut allergy the same thing as a peanut allergy?

Peanut allergies and tree nut allergies have identical symptoms, but they aren’t the same. Here’s how they’re different:

Peanut allergy

  • Type of nut allergy
  • An allergy to just peanuts
  • Peanuts are technically a legume, and they grow underground

Tree nut allergy

  • Type of nut allergy
  • An allergy to nuts that grow on trees
  • Includes almonds, cashers, coconuts, walnuts, and others
  • Tree nuts grow on trees (not underground like peanuts)

It’s not uncommon to be allergic to tree nuts and peanuts. But, if you’re allergic to one, that doesn’t mean you are definitely allergic to the other.

Can babies outgrow peanut allergies?

Are peanut allergies genetic?

Are airborne peanut allergies real?

Should I see a doctor if my child has mild symptoms of peanut allergy?

Can a peanut allergy come back even if my child has outgrown it?