Food Allergies 101: What You Should Know as a Parent

Allergies can be confusing, especially for parents of babies. Choosing when to introduce your baby to allergens can be a difficult decision as it depends on if they are developmentally ready. Although it may appear to be guess work, there is scientific evidence explaining how to go about introducing your baby to allergenic foods.

Recent research has shown that there are proactive steps parents can take to minimize the likelihood of a severe allergic reaction. This article will guide you through everything you know about childhood food allergies so you can confidently feed your baby. 

What are the most common allergies in Babies?

The food groups that cause around 90% of allergic reactions in children are: 

  1. Milk 
  2. Shellfish
  3. Eggs
  4. Fish
  5. Cow’s milk
  6. Tree nuts 
  7. Peanuts
  8. Wheat
  9. Soy

Cow’s milk, peanuts, and eggs are the most common allergies in babies and children.

How common are food allergies?

Research has shown that 5.6 million American children have allergies. This figure equates to 1 in 13 children or two in each American classroom. 40% of children with a food allergy are allergic to more than one food, showing you just how common they are. 

Are food allergies in babies increasing?

Yes. Between 1997 and 2011, the prevalence of food allergies increased by approximately 50%, according to the CDC. No one is quite sure what has caused this rise. Experts have suggested everything from environmental changes to our increase in hygiene. 

What causes a food allergy?

Allergic reactions are caused by the immune system wrongly identifying food proteins as attackers. When a foreign body or pathogen enters the body, our immune system jumps into action to attack and destroy it. The body releases a range of chemicals, including histamine, which cause the symptoms of an allergic reaction. 

What does an allergic reaction look like?

Symptoms of an allergic reaction to food in babies commonly include: 

  • Wheezing
  • shortness of breath
  • low blood pressure
  • face, mouth or throat swelling
  • itching
  • red hives
  • abdominal pain
  • nausea
  • diarrhea

Any sign of discomfort after eating is distressing and should not be overlooked. If you have any concerns about your baby’s condition, never hesitate to reach out to a medical professional. 

The most extreme reaction is anaphylaxis. Anaphylaxis can lead to constricted airways, swelling of the throat, a severe drop in blood pressure, and shock. If your baby shows any signs of anaphylaxis like trouble breathing, call 911 immediately.

How long does it take for an allergic reaction to occur?

Symptoms of a food allergy can appear immediately, but in most cases will occur within 2 hours of digestion. In some rare cases, the reaction can take up to two days to become clear. 

Is it possible to prevent food allergies in children?

Just two decades ago, doctors advised parents to avoid common allergens. This advice extended from pregnancy throughout breastfeeding until children turned 3 years old. Today, the advice is to the contrary. 

In 2000, the American Academy of Pediatrics (AAP) gave the advice above. 8 years later (2008), they published a report stating they could not find sufficient evidence for this advice. They reduced the age to 6 months. 

In 2009, researchers noticed that peanut allergies in Jewish children living in the UK were ten times more common than Jewish children growing up in Israel. They believed that it must be down to their food habits since their genetics were so similar. At the time, the prominent advice for parents in the UK was to avoid peanut products until the age of 3. Israeli children, however, frequently ate Bamba, a peanut butter corn-puff snack. 

The researchers decided to investigate their theory. They studied 600 high-risk babies (those with severe eczema or an egg allergy) in two randomly selected groups. The first group ate peanut products daily, while the other group avoided peanut products entirely. When the children reached the age of 5, they tested for a peanut allergy. Only 3% of those in the consume group had an allergy, compared to 17% of those in the avoid group. 

This historic study is known as the LEAP Study, and they continue their research today. They found that early exposure decreased the likelihood of developing a peanut allergy. 

The SPADE study, which studied cow’s milk allergy in children, had similar results. In 2019, the AAP revised their advice for parents to say that introducing common allergens to children as early as possible was the best course of action. 

Is there a cure for any food allergies?

Unfortunately, there are currently no cures for food allergies. The only way to manage them is to avoid the foods that can cause allergic reactions and carry an EpiPen where necessary. 

However, as we addressed above, prevention is the best gift you can give your baby. Introduce common allergens early, and they’ll be much less likely to develop a food allergy later in life. 

How likely is my baby to develop a food allergy?

Some factors put children more at risk of developing a food allergy. These are: 

  • An existing food allergy 
  • Another known allergy 
  • Eczema 
  • Asthma 
  • History of asthma in the family 
  • A parent with a food allergy 
  • A sibling with a food allergy 
  • Another family member with a severe allergy 

My baby meets this criteria. Should I get my child tested before introducing allergenic foods?

Despite meeting these criteria, the most recent AAAAI guidelines suggest that this is unnecessary. In fact, neither screening nor testing are necessary prior to introducing your baby to allergenic foods. If your baby is considered at higher risk for developing a food allergy, early introduction is highly recommended and can effectively reduce the likelihood that they develop an allergy.

What does an allergy test involve?

There are a few different types of allergy tests. They are: 

  • Skin Tests
  • Pin-Prick (AKA Scratch): the suspected allergen is mixed in a small quantity with a liquid. It is then applied to the skin with a tool that almost imperceptibly punctures the outer layers. Your baby is then observed for rashes, redness, itchiness, and swelling. This is the most common form of testing for babies. 
  • Intradermal: they inject a tiny amount of the allergen into the outer layer of skin and observe. 
  • Patch: this type is not often used for babies. It involves securing allergen-covered adhesive patches to the body. 
  • Blood: this is one of the best ways to identify multiple allergies at once.
  • Elimination Diet: this can be used effectively by parents to eliminate specific foods from your baby’s diet to determine the cause. It should also be noted that the inverse can also be used: introducing your baby to one allergen at a time and stopping if there is an allergic reaction. 

My baby already has a food allergy; how should I introduce new foods? 

Firstly, since your baby is considered high-risk for developing multiple food allergies, it’s best to consult with your health care provider. Once you’ve received feedback from a medical professional, you can confidently start introducing new foods (upon their recommendation).

New foods should always be introduced slowly. Increase the frequency until you are confident they are not allergic to that food, and then move on to the next. Never introduce two new foods at the same time as it will be difficult to pinpoint which food is causing a reaction (if a reaction were to occur).

Do children outgrow food allergies?

It’s common for children to outgrow milk, egg, wheat, and soy allergies. However, some experts believe children today outgrow food allergies more slowly than in previous decades, with many children remaining allergic after 5 years old. 

It should be noted that allergies to peanuts, tree nuts, and shellfish are generally lifelong allergies. 

How early can I introduce allergens to my baby’s diet?

Today, it is highly recommended  to feed your baby allergens in small amounts early on to prevent food allergies from developing. 

Modern research generally suggests that you start introducing common allergens as soon as your baby can eat solid (or mushy) foods. Just remember to keep the amount you introduce small and age-appropriate. The SPADE study found that just 10ml of cow’s milk-fed over the course of a week was enough to significantly reduce the likelihood of developing a cow’s milk allergy. A small amount of thinned peanut butter is far safer and more appetizing than a whole peanut. 

Key takeaways for parents

  • It’s important to remember that, in many cases, food allergies are potentially avoidable
  • There still needs to be further research on other allergens, but the AAP and AAAAI guidelines recommend introducing allergens as early as 4 months of age 
  • You do not need to avoid allergenic foods throughout pregnancy and breastfeeding 
  • Introduce one new food at a time, starting off with a small amount of each new food

As a concerned parent or guardian of a baby with an allergy, it is often tempting to avoid other potential allergens. However, we now know that this is not conducive to reducing the risk of developing an allergy, and in fact, can have the reverse effect. 

The first goal should be to prevent allergies using early introduction strategies. You as a parent can help prevent up to 80% of food allergies and save your baby from a potentially life-long food allergy


All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease. 

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