No parent wants her baby to have a food allergy, but it’s important that you know the signs of a baby food allergy, so that you act quickly to prevent it from getting worse. In this article, you will learn the basics of food allergies in babies, including symptoms of an allergic reaction, common foods that trigger allergies, and when to call 911.

Food allergies in children are on the rise. According to 2011 statistics from the U.S. Centers for Disease Control and Prevention, nearly 5 percent of all children under age 18 have a food allergy. In 2000, only 3.5 percent of kids had food allergies.

What is a Food Allergy?

When a baby eats a food that he or she is allergic to, that baby’s body reacts to that food like it is a foreign invader. The immune system produces disease-fighting antibodies (called immunoglobulin E, or IgE) to fight the “invader.”

So, whenever your baby eats that specific food again, the IgE antibodies launch a full immune-system attack on that food. The antibodies release histamines to attack the “invader.” Histamines are chemicals that are responsible for causing allergy symptoms.

Baby food allergies can develop in any infant, but they are more common in babies who have a family history of allergies, eczema, hay fever, and asthma.

It is possible that some babies may have a genetic disposition towards getting allergies, but not a specific allergy. For example, if one parent has a food allergy, pet allergy, or hay fever, their baby has a 50 percent chance of getting allergies too, but probably not the same exact allergy as the parent. Unfortunately, if both parents have allergies, their child has a 75 percent chance of becoming allergic to something.

Common Food Allergies in Babies 

There are over 160 food allergy triggers, but in 90 percent of baby food allergies, there are eight food groups that cause 90 percent of allergic reactions. The common foods that trigger allergies in babies include: 

1. Cow’s Milk
2. Eggs
3. Peanuts
4. Tree nuts – like almonds, walnuts, cashews, Brazil nuts
5. Fish – such as cod, tuna, salmon
6. Shellfish – like shrimp, crab, lobster
7. Soy
8. Wheat

Although peanut and nut allergies get a lot of press, it may surprise you that they are not the number one most common allergy in babies.

The most common food allergy in babies (and young children) is cow’s milk.

An estimated 1 in 40 children are allergic to cow’s milk (and dairy products). Cow’s milk food allergy is three times more common as a peanut allergy, and two times as common as an egg allergy.

Baby Food Allergy Symptoms

Signs of a food allergy in babies typically appear within several minutes or a few hours after your baby has eaten a specific food. Food allergy symptoms can be mild or severe. A severe allergic reaction to a food can lead to an emergency called anaphylactic shock, and it requires you to call 911 immediately.

Common symptoms of food allergies in babies include:

• Hives – raised, red, itchy bumps on the skin
• Itchy skin
• Swelling in the face, arms, or legs
• Runny or stuffy nose
• Sneezing and watery eyes
• Red rash around the baby’s mouth
• Vomiting
• Diarrhea
• Coughing

All babies react differently to food allergies, but skin reactions – hives, mild swelling, itchy skin, red rash – are the most common signs that your baby has a food allergy.

Sometimes, babies can have an allergic reaction to a food that they’ve eaten in the past. For example, a baby who is allergic to yogurt might not display any signs of a food allergy the first few times that she tried it. But eventually, if she is allergic to dairy, she will show allergy symptoms.

Allergic reactions to food aren’t always immediate. Sometimes, baby food allergy symptoms can be delayed. Your baby’s body may take longer to display symptoms. When a delayed allergic reaction to food occurs, your baby may experience:

• Constipation
• Diarrhea
• Colic
• Reflux
• Eczema

Because these delayed food allergic reactions are common in non-allergic babies, there may be other reasons for the symptoms.

When to Call 911 for an Allergic Reaction

It is rare for babies and young children to have a severe allergic reaction to food. But when it happens, it can be seriously scary for a new parent.

A severe allergic reaction is called anaphylaxis, and it can be life threatening. Your baby’s immune system overreacts to an allergen, and the entire body is affected. Signs of a severe allergic reaction include:

• Wheezing
• Trouble breathing
• Fainting, or loss of consciousness
• Extremely pale skin and sweating
• Rapid pulse

Symptoms of anaphylaxis can appear within two hours after your baby has eaten the food. Fortunately, anaphylaxis is rare in infants under six months old. It’s rare, but it can happen.

In the United States, you need to dial 911 if your baby seems to have difficulty breathing, or she is experiencing severe diarrhea or vomiting after eating. (Call your local emergency number if outside the U.S.) Do not attempt to drive to the emergency room yourself. You need paramedics and emergency personnel to help you immediately.

A severe allergic reaction can be life threatening, because there is a chance that your baby’s airways can close-up and she will be unable to breathe.

Do Babies Outgrow Food Allergies?

Although food allergies are scary, many babies do outgrow them by the time they start going to school. Soy and wheat allergies are typically outgrown the most.

Studies have indicated that 90 percent of children with milk and egg allergies will outgrow them.

Only 20 percent of babies with peanut allergies will outgrow theirs. Unfortunately, food allergies to peanuts, fish, shellfish, and tree nuts are typically lifelong food allergies.

Food Intolerance vs. Food Allergy

Keep in mind that only five percent of children (under age 18) have food allergies, but 20 percent of all Americans suffer from food intolerance.

When you have a food intolerance to something, your immune system doesn’t attack that food – like it does with an allergy. Instead, you have difficulty digesting that specific food. Your system is more “sensitive” to that particular food. The most common food intolerance is lactose intolerance. Children and adults who are lactose intolerant do not have the enzyme that their body needs to break down and digest cow’s milk and dairy products.

Food intolerance in babies typically causes gastrointestinal upset. After eating a certain food that they are intolerant or sensitive to, you may notice that your baby experiences:

• Gas
• Bloating
• Diarrhea
• Reflux
• Colic

If you’ve noticed that your baby gets bloated, has gas, or has tummy upsets after eating a specific food, he or she may have an intolerance to that food.

Baby Food Allergy – Can It Be Treated?

If you think that your baby might have a food allergy, you should talk to your child’s pediatrician or doctor. It’s a good idea to keep a food diary to help identify the specific food that you believe your baby is allergic to.

Some pediatricians can help diagnose food allergies, but sometimes, you will be referred to an allergist, who may ask your permission to perform an allergy skin test or blood test to see if your baby’s allergic symptoms are caused by an immune system reaction.

If the test is positive and there are IgE antibodies in your baby’s blood, then your baby has a food allergy. If the test comes back negative, your baby’s symptoms are probably due to a food intolerance.

For babies with food allergies, there is no medication that can help “cure” your child. The shots that they give for hay fever do not help with food allergies. As a parent, the best option you have to prevent an allergic reaction is to avoid the food that your baby is allergic to.

Your baby’s doctor will have more specific guidance on how to handle and manage your child’s food allergy. You may be given certain allergy medications to give to your child.

If your baby has a food allergy, you must be vigilant in reading food labels, since ingredients can show up in the most unexpected products. You will need to do careful planning if you’re eating out a restaurant.

As your child gets older, you should always bring your child’s allergy medication with you. If your doctor prescribed you an adrenaline pen (like EpiPen Jr.), you should keep this handy at all times.

If you ever have any questions about food allergies in your baby, contact your baby’s pediatrician.