How Can I Tell if My Baby Has Food Allergies?

Signs and Symptoms of Allergies in Babies

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Food allergies can be hard to spot in babies. It’s important to know what the symptoms are and how to recognize them in your child.

About 3% of infants are allergic to at least one food, and almost 9% of 1-year-olds. They are at higher risk if they have a close family member with food allergies. Common allergy triggers are cow’s milk, soy, and eggs.

Some babies may react to proteins from these foods in breast milk. Others react only when they eat the problem food.

Symptoms of a food allergy can be mild or severe. Always get emergency medical attention for a severe reaction.

In this article, you’ll learn the symptoms to watch for, how to recognize them in your baby, and what’s considered mild or severe.

You’ll also learn how long it takes to see symptoms and how to prevent allergic reactions in your child.

baby eating from spoon
brusinski / Getty Images
Body Part Symptoms  Severe? 
Eyes Itching, watering, swelling No
Nose Stuffy, runny, itchy, sneezing No
Mouth Swelling, itching No
Throat Hoarseness, coughing, swelling Sometimes
Lungs Difficulty breathing, wheezing Yes
Heart Low blood pressure, pale skin, loss of consciousness Yes
Digestion Nausea, vomiting, abdominal pain, reflux, diarrhea No
Skin Itching, eczema, hives, swelling No

Signs and Symptoms of a Food Allergy

Food allergies can cause a lot of symptoms, some of which may be hard to recognize in a baby who’s too young to tell you what’s going on.

If a parent or biological sibling has food allergies, your baby is considered high-risk for developing them. It’s especially important to watch for reactions in a high-risk baby.

Most food allergy symptoms are considered mild reactions. However, some can be severe and require immediate medical attention.

Mild

Mild food allergy symptoms in your baby may be hard to tell from other ailments. The key is to watch what symptoms tend to happen together and whether they come on soon after eating.

Colic

Colic isn’t a specific illness or diagnosis. It’s a descriptive term that means your baby cries inconsolably for at least three hours a day, three days a week, for at least three weeks.

It’s usually a predictable pattern. You can recognize a colic spell by its symptoms:

  • High-pitched crying
  • Hard to soothe
  • Red face, possibly with pale skin around the mouth
  • They may pull legs up, stiffen arms, clench fits, or arch the back

While a food allergy may cause colic, so can several things. These include being overstimulated, an inability to self-soothe, or a digestive problem other than allergies.

There’s no way to distinguish allergy-related colic from any other type of colic. Instead, pay attention to any other symptoms that may come with it.

It Might Be Reflux

Doctors now believe that some babies with colic have acid reflux (GERD). A percentage of those babies may have a cow’s milk allergy that is causing their reflux.

Your pediatrician can prescribe reflux medication or may suggest switching to a different formula.

Itching

A food allergy can cause itching all over. It may be hard to tell for sure if your baby has this symptom.

Before they’re old enough to be able to scratch an itch, an itchy baby may squirm in an attempt to rub the itchy spot against something. They may also be fussy.

Again, a suspected itch isn’t enough to suggest a food allergy. But it’s an important part of the whole picture.

Eczema

A baby has red, scaly eczema patches on the cheek.


panida wijitpanya / Getty Images

Eczema is a scaly, itchy rash that may become red and raw. It can look different depending on your child's age:

  • 0-6 months: Eczema is usually on the cheeks, chin, forehead, and scalp. Sometimes it spreads to other areas as well. It may look red and weepy.
  • 6-12 months: Eczema is most often on the elbows and knees, where the skin is rubbed from crawling. An infected rash may form a yellow crust.
  • 2-5 years: Eczema is most likely to be in the creases of the knees and elbows or on the wrists, hands, and ankles. It may look dry, scaly, and thick.

Eczema is rare in the diaper area because of the extra moisture there.

For babies who are high risk or already have eczema, research shows that two things can reduce the number and severity of eczema flare-ups in the first four months of life:

To soothe your baby’s skin, your pediatrician may recommend:

  • Oatmeal baths
  • Nonsteroidal lotions such as petroleum jelly
  • Cold compresses
  • Wet wraps

For severe itching, they may recommend antihistamines or steroid cremes.

Hives

Hives are pink or red bumps with pale centers. They can be quite itchy. Hives from food allergies are widespread (all over the body) and usually go away on their own within about six hours.

Hives can be anywhere from half an inch to several inches across. Their shapes may be irregular and they can show up anywhere. They may disappear from one area only to turn up in another.

Red hives cover the majority of a toddler's torso.

Kwangmoozaa / Getty Images

Hives themselves aren’t an emergency. But when they’re widespread, they can point to an allergic reaction or an infection. Only about 3% of hives come from food allergies.

If hives are just in one area, it’s more likely due to something they’ve had physical contact with, like pet saliva or pollen.

Oral Allergy Syndrome

Some babies get hives, itching, or swelling around their mouths after eating raw fruits and vegetables. This is from oral allergy syndrome, which is a minor reaction.

Mild hives don’t need to be treated. They should go away on their own.

To treat hives at home, use an allergy medicine that’s appropriate for your child’s age. If you’re not sure what to use, call your pediatrician.

If they’re over a year old, Benadryl is often the first choice. It may not be safe for younger babies, though.

Get medical care right away if your baby:

  • Develops hives after eating nuts, eggs, fish, or shellfish
  • Develops hives after taking medicine
  • Has widespread hives and is under a year old
  • Acts or looks sick
  • Has symptoms you're concerned about

Food allergies can lead to anaphylaxis, which is life-threatening. This happens with sudden-onset hives plus difficulty breathing or swallowing. The danger zone for anaphylaxis is between 30 minutes and 2 hours after exposure.

Call 911

Get emergency medical attention if your baby:

  • Has hives less than two hours after being exposed to something you know they’re allergic to
  • Suddenly has a cough or sounds hoarse
  • Has trouble swallowing
  • Has unusual drooling
  • If they talk, has slurred speech

Swelling of the Face, Lips, and Eyes

Your baby may take on a “puffy” look in their face, and especially in the lips and around the eyes. This is called angioedema.

Treating the allergy will help the angioedema go away.

Watch for Breathing Problems

Facial and lip swelling could be accompanied by swelling in the tongue and throat, which can become a medical emergency if it impairs breathing.

Digestive Issues

Food allergies can lead to several digestive symptoms:

  • Abdominal pain: It’s hard to gauge this in a baby. Some signs may be crying inconsolably and pulling their knees to their chest.
  • Vomiting: Be sure not to lay your baby down if they’ve been vomiting as they may aspirate (breath vomit into their lungs).
  • Loose stools or diarrhea: This may contain mucus or blood.

If your baby has chronic vomiting or blood or mucus in her diaper, your healthcare provider may want to do some diagnostic testing. They may suggest switching to a prescription hydrolyzed formula.

With vomiting and/or diarrhea, do your best to keep your baby hydrated. If they can’t keep anything down or start showing signs of dehydration, get medical help right away.

Dehydration Symptoms

  • No tears when they cry
  • Dry lips and tongue
  • Low number of wet diapers (six a day is normal for infants)
  • Sunken eyes
  • Sunken soft spot
  • Dry, wrinkly skin
  • Deep, rapid breathing
  • Cool, blotchy hands and feet

Classic Allergy Symptoms

A food allergy can give your baby the classic allergy symptoms:

  • Stuffy, runny nose that can become chronic (allergic rhinitis)
  • Sneezing
  • Coughing
  • Itchy, watery eyes

These symptoms are generally treated with allergy medications.

Recap

Symptoms of a mild allergic reaction include:

  • Colic
  • Itching
  • Eczema
  • Hives
  • Swelling of the face, lips, and eyes
  • Digestive issues (vomiting, diarrhea)
  • Classic allergy symptoms (sneezing, runny nose)


Severe

A severe allergic reaction is called anaphylaxis or anaphylactic shock. Anaphylaxis is rare in babies.

Symptoms are most likely to come on right after your baby has been introduced to a new food or formula. Along with the allergy symptoms above, watch for:

  • Wheezing, difficulty breathing: Listen for a whining or rattling sound. They may gasp for breath or purse their lips to breath.
  • Swelling of mouth, face, or throat: This may impair breathing or swallowing.
  • Choking: This is a sign of respiratory distress.
  • Pale, flushed skin: This symptom may be hard to spot if your baby has hives. It may indicate dropping blood pressure.
  • Loss of consciousness: This is a sign of dangerously low blood pressure. Call 911.

Call 911

Anaphylaxis is a life-threatening emergency. If your baby is having trouble breathing or has a swollen face, tongue, or throat, call 911 immediately.

When Do Symptoms Appear?

Symptoms of a food allergy generally appear quickly—within a few minutes after your baby eats the food.

Anaphylaxis develops between 30 minutes and 2 hours of eating the problem food.

Your baby may tolerate a food fine at first but develop an allergy later. Allergies can develop at any point in life.

Foods Most Likely to Cause an Allergic Reaction

Any food can trigger an allergic reaction. However, 90% of them are caused by:

The majority of kids who are allergic to milk, eggs, wheat, or soy outgrow their food allergies by the time they’re 5 years old. Others may last longer or be permanent.

Recap

Symptoms of a severe allergic reaction include wheezing, difficulty breathing, swelling of the mouth and throat, and, if blood pressure drops dangerously low, pale skin and loss of consciousness.

Severe allergies are a medical emergency. Call 911 if your child could be having a severe reaction.

Food allergy symptoms generally appear within minutes of eating the problem food. Anaphylaxis can occur within a two-hour window.

Foods most likely to be a problem are milk, eggs, wheat, soy, peanuts, tree nuts, fish, and shellfish.

Preventing Allergic Reactions

The best way to minimize your baby’s risk of allergic reactions is to breastfeed. It’s the least likely thing to trigger a reaction.

However, if your baby appears to have a reaction to your breast milk, it may be because they’re allergic to proteins from food you’ve eaten that are passed on through your milk.

Breastfeeding for between four and six months may reduce your baby’s risk of eczema, wheezing, and an allergy to cow's milk.

Once your baby is between four and six months old, introduce solid foods with single ingredients, like apple or squash baby food, or rice cereal. Start with foods unlikely to cause an allergy and bring in potentially allergenic ones a little later.

Space out new foods by a few days. Then if your baby does have a reaction, it’s easy to figure out what food is the problem.

Some people wait to give their baby higher-risk foods like eggs and peanuts. But experts say delaying exposure to those foods may actually increase their risk of food allergies.

If you don’t have allergies, it’s not necessary to avoid possible food allergens during pregnancy and breastfeeding. There’s no evidence doing so prevents allergies in the baby.

Once you know your baby is allergic to something, the best way to prevent a reaction is to diligently avoid the problem food(s).

Summary

About 3% of infants have food allergies. Symptoms of a mild reaction can include colic, eczema, hives, vomiting, diarrhea, sneezing, and runny nose.

Severe reactions are called anaphylaxis and involve wheezing or difficulty breathing, swelling of the mouth and throat, and possibly loss of consciousness. Anaphylaxis is always a medical emergency.

Allergy symptoms appear quickly after eating. A severe reaction can happen within two hours. Common allergy triggers include milk, eggs, wheat, soy, nuts, fish, and shellfish.

You can prevent allergic reactions by breastfeeding and introducing single-ingredient foods one at a time. Don’t delay introducing foods that are high-risk for allergies as early exposure may help prevent food allergies.

If your baby reacts to proteins from certain foods in your breast milk, you may need to avoid that food. However, there’s believed to be no preventive benefit of avoiding potential allergy-causing foods during pregnancy or breastfeeding.

A Word From Verywell

It can be frightening and stressful to have a baby with a food allergy. You’ll need to be especially vigilant about their diet and prepared for an emergency.

The good news is that many children ultimately outgrow food allergies. In fact, the earlier the child’s first reaction, the more likely they are to outgrow it.

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