If it seems like every other tot you know is allergic to something, there's good reason. Though the jury is still out on the cause, researchers are certain about one thing: Food allergies in children are on the rise.

Because allergies tend to run in families, if you or your spouse — or both of you — are allergic to something (including pollen, mold or pets), your baby or toddler may have an elevated risk of allergies too.

Is it possible to lower your child's odds of developing a food allergy? How can you tell if your baby or toddler is allergic to a certain food or foods? And what can you do to treat an allergic reaction? Read on for the answers to these and other questions about food allergies in children.

What causes food allergies in babies and toddlers?

Food allergies in babies and toddlers occur when the body’s immune system treats a food as a potential threat. That over-the-top immune response causes your baby’s bad reaction, which can range from mild to severe. 

If your little one is having skin, stomach or breathing problems, a food allergy might be the culprit. About 8 percent of U.S. children have and are affected by a food allergy, according to a study published by the American Academy of Pediatrics (AAP) in its journal Pediatrics.[1]

That’s an increase from a decade ago, when about 5 percent of children under 18 in the U.S. had food allergies, according to an earlier study by the Centers for Disease Control and Prevention (CDC).

What are the symptoms of food allergies in babies and toddlers?

Fortunately or unfortunately, depending on how you look at it, symptoms of food allergies in babies, toddlers and other children are rarely subtle and sometimes occur just minutes after eating.

Telltale signs usually appear within the first 30 to 120 minutes (i.e. one to two hours) after exposure to the offending food. In rare cases, symptoms are noticeable after as many as four to six hours or even longer. They can include:

  • Hives (red spots that look like mosquito bites)

  • Itchy skin rashes (eczema)

  • Itchy, watery or swollen eyes

  • Skin swelling

  • Lip and/or tongue swelling

  • Sneezing

  • Wheezing

  • Throat tightness

  • Difficulty swallowing

  • Nausea

  • Vomiting

  • Stomach pain

  • Diarrhea

Severe symptoms — including trouble breathing, lightheadedness and loss of consciousness/passing out — thankfully are rare. If you spot them, call 911 right away.

High-allergy foods for babies

While any food can potentially cause an allergic reaction in babies, toddlers and other children, certain foods are much more likely to trigger symptoms.[2] These eight foods account for 90 percent of food allergies:

  • Milk

  • Eggs

  • Peanuts

  • Tree nuts (including almonds, brazil nuts, cashews, chestnuts, filberts, hazelnuts, hickory nuts, pecans, pistachios and walnuts)

  • Soy

  • Wheat

  • Fish

  • Shellfish (such as crab, lobster and shrimp)

The most common high allergy foods in a baby’s first year include cow’s milk, peanut and egg. Certain foods, particularly peanuts (which are actually legumes), tree nuts and seafood, are the most common triggers of severe allergic reactions.

Roughly 30 percent of children who have peanut allergies are also allergic to tree nuts, so check in with your pediatrician before feeding your baby an almond-butter sandwich for lunch.

Introducing food allergens to your baby

Although for some time it was common to delay giving children dairy foods until age 1, eggs until age 2, and seafood and nuts until ages 1 to 3, evidence suggests there’s actually no reason to wait.

AAP guidelines say that the early introduction of foods such as peanuts (in the form of thinned-out peanut butter or another safe-to-eat peanut snack at this age) as early as 4 to 6 months may actually prevent peanut allergy in infants at "high risk" for it.[3] 

If your baby does not have severe eczema or other food allergies (and therefore is not considered to be at an increased risk for developing a food allergy), he can have foods such as eggs, fish, peanut-containing products and other highly allergenic foods freely after a few solid foods have already been introduced and tolerated without any signs of allergy. 

When it’s time to introduce your baby to solid foods, make sure he has tried and tolerated other less-allergenic solids (like fruits, veggies and infant cereal) first.

Each time your little one tries a new, single-ingredient food, wait two to three days before moving on to another food, and watch for possible allergic reactions such as diarrhea, rash or vomiting. If all goes well, you can gradually add allergenic foods to baby’s diet.

Always introduce new foods at home instead of at day care or a restaurant, and keep a close eye on your baby or toddler for allergic reactions one to two hours after mealtime. Monitoring can be challenging, considering it may coincide with naps or bedtime.

If he seems like his typical, bubbly, adorable self, he's in the clear. If you spot any symptoms of a food allergy, call your pediatrician right away. However, if the reaction is severe and life-threatening (difficulty breathing, passing out) call 911 and seek immediate care.

To play it safe make sure, as with all infant foods, that allergenic foods are given in age- and developmentally-appropriate safe forms and serving sizes.

For example, when introducing peanuts, stick with a thin layer of creamy peanut butter or a peanut puffs snack and avoid whole peanuts or chunky peanut butter, which could pose a choking risk.

One way to introduce peanut butter is to thin a small amount and mix it into yogurt or cereal. You can also spread it very thinly on bread. When it comes to whole peanuts, the AAP says not to serve them to children before 4 years of age — that’s the age when kids should be able to chew them well. 

Babies with mild or moderate eczema are at an increased risk of peanut allergy, and it’s therefore recommended they try peanut products and other highly allergenic foods at around 6 months of age. Of course, talk with your pediatrician about your child's situation and needs before serving him these things.

Testing for peanut allergy is recommended for babies with severe eczema or egg allergy. Talk to your doctor early — around the 2- or 4-month check-up — since ideally your child should be given peanut butter once solids are started by 6 months old. Your practitioner will be able to advise you on how and when to get your child tested.

How is a food allergy diagnosed in babies and toddlers?

If your baby or toddler appears to be allergic to a certain food, talk to your child's pediatrician.

If your doctor suspects a food allergy, they’ll likely recommend talking with a pediatric allergist, who may suggest a blood test (that screens for allergy antibodies) or a skin-prick test (scratching a small amount of the allergen into the skin and looking for a reaction) to confirm the diagnosis.

A positive test doesn’t always mean there’s a food allergy or show how severe an allergic reaction will be. It may only suggest that a child is sensitive to a particular food or foods.

What’s the difference between a food allergy and a food intolerance in babies?

How can you tell the difference between a food allergy and a food intolerance in your baby or toddler? Intolerance can be affected by how much your baby eats or drinks. With a food intolerance, your tot might have gas and an upset tummy after drinking a full cup of milk (after 12 months). But with a food allergy, ingesting even a small amount can trigger a reaction that affects many parts of the body.

What's more, while kids who have an intolerance to milk may be able to eat other dairy foods like yogurt, cheese or ice cream with no problem (especially if they're lactose-free), cow's-milk-allergic kids can’t eat any dairy foods at all without having a reaction and may also be allergic to milk from goats or sheep.

An allergy is an immune response gone wrong. It happens when the immune system attacks a substance (like a food), mistakenly thinking that the substance is an invader. In an effort to defend the body from the offending food, the immune system produces histamine (an inflammatory chemical), which causes symptoms such as itchiness and swelling.

An intolerance to food, on the other hand, has nothing to do with the immune system; it has to do with the digestive system. It occurs when the body lacks one or more digestive enzymes needed to break down an ingredient in a particular food. This causes stomach upset, like gas and bloating.

The tricky part is that food allergies and food intolerances often result in some of the same symptoms. Again, if you’re not sure if your child is allergic, a pediatric allergist can make a diagnosis with blood or skin tests.

Can kids outgrow food allergies? 

Will your baby or toddler always be allergic to certain foods? Maybe not. The majority of babies and toddlers who have milk, egg, wheat and soy allergies outgrow them by the time they’re 5 years old.

And surprisingly, about 20 to 25 percent of kids with peanut allergies — once thought to be lifelong — outgrow those too (by around age 8). However, allergies to shellfish, fish and tree nuts often last a lifetime. 

Never experiment on your own to determine whether your child is no longer allergic: Your pediatrician or pediatric allergist can do a supervised feeding test to make a diagnosis.

How do you treat an allergic reaction in babies and toddlers?

No matter how hard you try, it can be virtually impossible to control everything that goes into your baby or toddler's mouth. That's why if he does have a food allergy, check in with your pediatrician about possible remedies and over the counter medications before you use them.

It’s possible that he or she may recommend having children’s antihistamines (like Benadryl) on hand, although this medicine is not for children younger than 2 years of age and only then with approval from the doctor. 

If your little one is prone to severe reactions, your pediatrician will give you a prescription for a pre-filled syringe with epinephrine (a hormone that reverses anaphylaxis by constricting blood vessels to increase blood pressure and opening airways to help with breathing).

A lower-dose epinephrine auto-injector with a shorter needle is available specifically for infants and toddlers weighing 16.5 to 33 pounds.

Make sure you and any of your baby or toddler’s other caretakers always know where the injector is and how to use it. And if you ever do need to use it, take your child to the emergency room for follow-up right away, because allergy symptoms can return.

Will my baby need allergy shots?

Here’s the good news: Food allergies aren’t treated with allergy shots, which are only given for environmental or seasonal allergies to children 5 and older.

The not-so-good news: The only way to “treat” food allergies is to avoid the food. That means you’ll need to become a pro at making sure your child avoids foods he's allergic to, both at home and when he's dining elsewhere.

Tips for keeping a baby or toddler with food allergies safe

Worried about navigating being the parent of a child with food allergies? Here are some tips to make it smoother sailing:

  • Let all your child's caregivers know about his allergies, how to tell if he is having an allergic reaction and what to do if he is exposed to an offending food.
  • Always keep safe food on hand (especially when you’re out).
  • Become an expert at reading food labels (milk, eggs and other allergenic foods are often listed by other names).
  • Consider consulting a registered dietitian nutritionist, who can help you navigate these issues and develop meals that are safe for your baby or toddler to eat.

Having a child with food allergies can be scary. As a parent, the key is to be prepared: Recognize the signs and symptoms of an allergic reaction, take steps to manage your child’s allergy and know when to administer epinephrine and call 911.