Parents often have concerns about when to introduce common food allergens safely into their child's diet. While food allergies may develop during childhood, they can occur at any age.

What are the most common food allergies in children?

Some of the most common food allergens in children include: 

• Peanuts.
• Tree nuts, such as almonds and cashews.  
• Cow’s milk.
• Eggs.
• Wheat.
• Soy. 

What are the signs of an allergic reaction?

Most people will experience symptoms within 30 minutes. A developing food allergy may show signs such as:

• Rash or hives.
• Itching of the tongue, lips or throat.
• Abdominal pain.
• Nausea, vomiting or diarrhea. 

Warning signs that require immediate medical attention:

• Trouble breathing.
• Shortness of breath or wheezing.
• Swelling of the tongue, lips or throat. 

Does introducing common food allergens early help?

Recent studies indicate a decline in the rates of common food allergies in children, thanks to introducing certain foods like peanuts earlier than previously thought. 

“Introduction of these common allergens in small amounts between ages four to six months can help reduce the risk of developing allergies to these foods,” says family medicine doctor Denai Gordon, MD. “Since implementing the recommendations for early exposure to allergens such as peanuts, cow’s milk and eggs, rates of food allergies have declined significantly.”

It is important to note, however, that food intolerance, such as lactose intolerance, is not a food allergy.

Food intolerances differ from food allergies in their causes. “Food intolerances are due to an issue with digesting a certain food or ingredient,” explains Dr. Gordon. “A common example of food intolerance is lactose intolerance. Ingesting foods or drinks containing lactose can cause an upset stomach, bloating and loose stools, but it is not triggered by an immune response. It is instead caused by a missing enzyme in the body.”

Is it common to outgrow allergies? 

Many children outgrow food allergies, but are more likely to outgrow allergies to cow’s milk, soy, wheat and eggs. They are less likely to outgrow allergies to peanuts, tree nuts or shellfish. 

Are some children more likely to develop food allergies than others?

Genetics may play a part. Children with a family history of eczema, asthma or allergies are at an increased risk of developing food allergies. In addition, children who currently have eczema, asthma or environmental allergies are also at higher risk.

“Earlier introduction in babies at age 4 months may help reduce the risk of developing food allergies in these higher-risk children,” adds Dr. Gordon. “Exclusive breastfeeding may reduce the risk of developing asthma or eczema, but not the risk of developing food allergies.”  

Should I get my child tested for food allergies?

Before testing for food allergies, a health care provider needs to obtain a thorough history to assess whether allergy testing is appropriate. Testing can be done with a blood test or a skin prick test.