Signs your child has a food allergy

A food allergy is an immune system response to something the body ingests—that something is called an allergen. If your body thinks the allergen is harmful it creates antibodies to fight it. A food intolerance is often mistaken for an allergy, but is a localized response (usually in the digestive system)—the offending food either irritates the digestive system or is unable to be digested. 

The 8 most common food allergens are milk, eggs, peanuts, tree nuts, shellfish, fish, soy, and wheat. 

Because children with food allergies are more likely to develop asthma and other allergies, it is important to have your child tested for allergies if he experiences a reaction to a certain food. An allergist or immunologist can examine your child and order a skin or blood test to determine whether the reaction is a food allergy, a food intolerance, or something unrelated.

Signs your child has a food allergy

You’ll know immediately if your child is allergic to a certain food. Symptoms often occur within five minutes (though they can occur later, usually within 30 minutes) and include: 

  • hives
  • itchiness
  • skin swelling
  • vomiting
  • diarrhea
  • respiratory symptoms

Though rare, anaphylaxis is a potentially life-threatening allergic reaction. A child’s airways narrow making it difficult to breathe. Anaphylaxis can occur within seconds of exposure to an allergen, particularly peanuts or tree nuts. Such severe allergic reactions require an immediate call to 911. 

How common are food allergies? 

It’s difficult to know the exact prevalence of food allergies in children (and adults). A lack of high-quality research on food allergies leaves us with conflicting and uncertain data. For instance, according to the National Institutes of Health (NIH), food allergies occur in 5 percent of children in the U.S. But according to the Centers for Disease Control & Prevention (CDC), 3.9 percent of children have food allergies. The National Institute of Allergy and Infectious Diseases (NIAID) reports that 5 percent of children under the age of 5 have food allergies. A 2007 study published in Immunology and Allergy Clinics of North America reports that 1-3 percent of adults and 4-8 percent of children have food allergies. And a NIAID review of existing research acknowledges a lack of uniform criteria in food allergy research, concluding that food allergies affect 1-2 percent but less than 10 percent of the population. 

While NIAID researchers say it’s unclear whether the prevalence of food allergies is on the rise, there are media reports that suggest it is, noting scientists are studying why food allergies are increasing. The American Academy of Allergy Asthma and Immunology (AAAAI) gives statistics supporting an increase in food allergies: Between 1997 and 2007, childhood peanut allergies alone doubled and the prevalence of all food allergies increased by 18 percent. Meanwhile, the number of anaphylaxis cases to foods increased from 21,000 per year in 1999 to 51,000 per year in 2008.

Reducing the risk of food allergy 

Recent research suggests that a child's risk of developing peanut allergy may be reduced by early, frequent ingestion of peanut-containing products from about 6 months of age (peanut crackers or puffs are recommended, since hard peanuts and sticky peanut butter are choking hazards). However, first consult with your child's pediatrician or specialist and consider allergy testing if your child is at higher risk of peanut allergy, as indicated by severe eczema, egg allergy, or both. And remember, early introduction will not prevent all cases of peanut allergy. While it can be a strategy for reducing peanut allergies, it will not eliminate peanut allergy for all children. (Learn more about peanut allergies here)

Some childhood food allergies are more temporary than others. Most children outgrow cow’s milk, egg, soy, and wheat allergies between the ages of 3 and 16 years, while about 20 percent outgrow peanut allergies and less than 10 percent outgrow tree nut allergies. 

Whether your child outgrows the allergy, you can stay safe by avoiding triggering foods. Remain vigilant about ingredients in restaurants, other people’s homes, and on food labels—the Food Allergen Labeling & Consumer Protection Act (FALCPA) requires products to list ingredients derived from the eight major food allergens. Your doctor might recommend that you carry injectable epinephrine (more commonly known as an EpiPen, which comes in pre-filled single doses, and relaxes the muscles in the airways) or antihistamines (over-the-counter drugs which reduce the effects of histamines, a chemical released during an allergic reaction). He may suggest that your child wear an ID bracelet or necklace identifying his allergies so that, in case of an allergic reaction, emergency responders can give the appropriate medical treatment. 

Some allergies may dictate a drastic change in your child’s diet to less processed food. If this is new territory for you, consider meeting with a nutritionist who can guide you to different, affordable food choices. 

Click here to view the most common food allergies and find out what you can do if you learn your child has a food allergy.

Last updated June 13, 2017

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