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Introducing your baby to solid foods can be such a fun and exciting time. But if you suspect your little one may have allergies, you might be worried about potential reactions — and for good reason!

Food allergies affect up to 8 percent of children in the United States.

While a family history of food allergies and similar conditions may be a clue that your baby will have allergies as well, it’s not always the best predictor.

Here’s how to get familiar with what a reaction looks like, learn how to spot a severe reaction, and understand the steps you’ll need to take to get your baby help.

Anaphylaxis is a severe allergic reaction that can be life threatening. If you suspect your baby may be having a serious reaction, call 911 or head to the nearest emergency room.

Symptoms may include:

  • mood changes, including crankiness or inconsolability
  • vomiting
  • loose stools
  • full-body rash or hives
  • swelling (angioedema) of the eyes, lips, or elsewhere
  • rapid heart rate (tachycardia)
  • difficulty breathing or shortness of breath
  • wheezing
  • lethargy
  • dizziness or fainting
  • scratching the skin

Researchers share that babies tend to have hives, wheezing, and vomiting more than other symptoms.

One of the features of anaphylaxis versus a mild reaction is that it may come on quickly — think 5 to 30 minutes — after exposure. Recognizing these signs in your baby is the most important step to getting help.

So, what exactly is an allergic reaction? Well, if your baby is exposed to a substance — like a food or beverage — that they’re allergic to, a reaction is their body’s way of defending itself.

When exposed to an allergen, the body releases histamines that cause inflammation. As a result, your baby may have anything from mild to moderate or even severe symptoms.

Mild or moderate allergic reactions can happen after your baby touches, swallows, tastes, eats, or breathes in something they’re allergic to.

Symptoms might include:

  • tingling or itchiness of the throat and mouth
  • swelling in the lips, eyes, or face
  • hives or rash
  • eczema
  • abdominal pain or vomiting
  • congestion, sneezing, or runny nose
  • dry cough

Even exposure to a tiny amount of a food they’re allergic to, like a piece of a peanut, can be enough to produce a reaction in some babies.

Of course, babies drool, spit up, and cry relatively often. They also don’t have the verbal skills to tell you something is wrong. Your baby may try to communicate that they’re not feeling well in some other way.

Pay close attention to your baby to spot these other possible signs of reaction:

  • scratching or pulling at their tongue
  • putting their hands in their mouth (in a way not typical for them)
  • having a hoarse or squeaky voice
  • pulling at their ears
  • unusual crying or behavior
  • any slurring in speech (if they’re already talking)

Again, one of the key features of a severe reaction versus a mild one is that it comes on soon after exposure.

Signs of anaphylaxis in babies tend to be milder than in older children and adults. The most reported symptoms of severe allergic reaction in babies are hives and vomiting.

In a 2018 study on 357 children ranging from infants to school-aged kids, researchers discovered that babies who have allergic reactions tend to have stomach issues 89 percent of the time.

Specifically, vomiting was present in 83 percent of severe reactions to foods. And a whopping 94 percent of babies experienced hives as part of their severe reaction versus just 62 percent of school-aged kids.

Only 17 percent of infants had breathing difficulties. In fact, just a single baby had wheezing.

And only one baby had low blood pressure as a result of their severe reaction, which is a hallmark sign of anaphylaxis in older children and adults.

That all said, it’s important to be able to identify any allergy signs in your little one, especially soon after consuming certain foods.

If your child has any of these signs, don’t hesitate to call 911 and get help. Even if you aren’t sure, it’s better to be safe than sorry.

Depending on the severity of the reaction, you’ll want to act fast to get your baby help — especially if this is their first reaction.

In particular, you’ll want to get emergency help (call 911) if your baby has:

  • shortness of breath
  • difficulty swallowing
  • coughing
  • a weak pulse

Combinations of other symptoms are also important to spot, like rash or swelling along with loose stools and vomiting.

If you’ve dealt with reactions before, your doctor likely prescribed an epinephrine pen (EpiPen) to use in cases of severe reactions.

Use this drug as directed, then call an ambulance or drive to the ER. Either way, be ready to do CPR if your baby stops breathing at any time.

Once medical staff arrive, let them know that you’ve administered epinephrine. You may need to give another dose of the drug if symptoms return.

If your baby does have a severe reaction, it’s important to keep an eye on them for 6 to 8 hours after treatment. That’s because there’s risk of rebound anaphylaxis (severe symptoms that recur), typically within 8 hours of the initial reaction in up to 20 percent of cases.

If your little one has a mild reaction, it’s a good idea to call and check in with their pediatrician.

They can tell you if there are any steps you should take or if your baby needs an appointment. The doctor may also order allergy testing so you can identify other possible allergens to avoid.

Related: What to expect when your baby has allergies

Most severe allergic reactions to foods will happen very soon after exposure. However, some milder reactions may take up to a few hours (usually around 2 hours) to become apparent.

Food allergies may be more common in families with a history of allergies and associated conditions, like asthma, eczema, or even hay fever.

The great majority of food-related allergic reactions are caused by one of the following:

  • nuts (tree nuts and/or peanuts)
  • fish
  • shellfish
  • eggs
  • milk
  • wheat
  • soy

Of all foods, babies are most likely to be allergic to:

  • milk
  • eggs
  • peanuts.

Though less common, some babies may be allergic to:

  • certain fruits
  • vegetables
  • legumes (beans, peas, lentils, etc.)

Babies and children can “outgrow” their allergies over time, though allergies to peanuts, tree nuts, fish, and shellfish may be lifelong.

Experts recommend exposing babies to high-risk foods before they reach their first birthdays. Research from 2015 supports the idea that earlier exposure to peanuts, for example, may lower the risk of developing a peanut allergy later on.

So, for example, you’ll want to cook eggs and prepare peanuts in age-appropriate ways (fully cooked eggs, smooth peanut butter) and offer them up to twice per week.

How to do it:

  • Try first rubbing a very small amount of an allergenic food on your child’s lips to observe any signs of reaction. (Remember: It can take minutes to hours for a reaction to occur.)
  • If all looks good, add around a quarter teaspoon of the allergenic food to your baby’s usual puree and mix well.
  • Over time, increase the amount of the allergenic food (by another quarter teaspoon) if you don’t observe an allergic reaction.
  • Don’t rub foods into your baby’s skin. It doesn’t help with identifying allergies — and it might actually increase the risk of your baby developing an allergy to that particular food.

If you have a family history of food allergies, speak with your doctor about early introduction to certain foods. Some pediatricians may suggest you give the food under medical supervision in case of a severe reaction.

Related: How to safely introduce your baby to peanuts and other food allergens

The tricky thing with food allergies is that your baby’s reaction may not always be the same severity. Allergy experts explain that food that causes a relatively mild reaction one time may cause a more severe reaction another time.

Unfortunately, there’s no specific drug or supplement you can take to prevent or treat food allergies as a whole.

Instead, the goal is to avoid foods that cause reaction and have emergency treatment available in the event that baby has been exposed.

Some tips for avoiding allergenic foods:

  • Read labels carefully. All the main food allergens should be listed in bold letters after the ingredients list for easy identification. If ingredients aren’t listed, try asking staff or skipping the food entirely.
  • Note that some labels might say “may contain” or “made on shared equipment” for certain ingredients. This type of labeling isn’t well regulated. Speak with a doctor or allergist if you have concerns about your baby eating these foods.
  • Have your child tested over time to see if they’ve outgrown their allergy. This is a more likely scenario with allergies to milk, eggs, wheat, and soy than it is with peanuts, tree nuts, shellfish, and fish.
  • Consider reaching out to a dietitian or nutritionist for help if you feel your baby’s allergy is restricting their diet. A food expert can help you make sure your little one gets the nutrients they need to thrive, all while being safe.
  • Look into getting a chef card. You can take it to restaurants to inform staff of your child’s specific allergy concerns. Cards are available in several different languages.

What about breastfeeding?

There’s no current evidence to support a restrictive diet while breastfeeding to prevent allergies in babies. Instead, work with a doctor for guidance on dietary changes only after your baby shows a potential reaction to a food.

The proteins from food reach breast milk approximately 3 to 6 hours after consumption. After eliminating allergenic foods, it may take between 1 and 2 weeks for your baby’s allergy symptoms to subside.

Speak with your baby’s pediatrician if you have any concerns about giving allergenic foods to your child. Your doctor should have the most up-to-date information about how to prepare and introduce these foods in the safest way possible.

Your child’s doctor can also help you get appropriate allergy testing if needed and develop a plan for cases of severe reaction so you’ll feel more confident in an emergency.