The Middlesex-London Health Unit is currently under a province-wide Stay-At-Home Order
COVID-19 Info | Information sur la COVID-19 | COVID-19 Self-Assessment | COVID-19 Lab Results

Middlesex-London Health Unit

Inner Nav

Food Allergies in Infants and Children

Approximately, six to eight percent of Canadian children under the age of 18 years self-report having at least one food allergy.1 Health Canada identifies the following as priority food allergens in Canada: peanuts, tree nuts, sesame, milk, eggs, fish (including shellfish and crustaceans), soy, wheat, sulphites, and mustard


Who is at high risk of food allergies?

An infant is considered at high risk of developing food allergies when they have a first degree relative (sibling or parent) with an allergic condition, such as atopic dermatitis, a food allergy, asthma, or allergic rhinitis.2 Having a food allergy does not cause atopic dermatitis, however, children with atopic dermatitis may be at increased risk of developing food allergies.3 Healthcare providers should help parents/caregivers manage eczema as healthy skin helps protect the immune system from exposure to food allergens, which may decrease the risk of food allergies.3

Will children outgrow food allergies?4

There are several factors that affect whether children will outgrow a food allergy. A child with multiple food allergies is less likely to outgrow their food allergies. If they do, they frequently outgrow their food allergies at an older age. The type of food allergy is also important. For example, children will generally outgrow milk and egg allergies sooner, than fish and nut allergies. The earlier a child’s first reaction, the more likely they are to outgrow their allergy. Research examining the effects of oral and sublingual immunotherapy is ongoing to determine whether tolerance can be induced.

Prevention of food allergies

During pregnancy and lactation:

  • Current research is inconclusive as to whether restricting the maternal diet during pregnancy and lactation will help to prevent food allergies. The risks of undernutrition and subsequent harm to the infant caused by restrictions in the maternal diet may be significant and should be avoided until further research is available.2
  • Similarly, restricting common allergenic foods from the maternal diet during lactation has not been shown to reduce the risk of food allergies in high-risk infants and should be avoided.5

In Infants and Young Children:

  • Healthcare providers should encourage exclusive breastfeeding with the introduction of iron-rich complementary foods at about six months of age.
  • Delaying the introduction of potential food allergens is not recommended and should be avoided. While it was previously thought that delaying the introduction of these foods may prevent food allergies, new research suggests that this may actually increase the risk of food allergies.2
  • When introducing a priority food allergen, parents/caregivers should introduce one at a time and wait 48 hours before introducing a different priority food allergen.
  • Once a priority food allergen has been introduced, it should be included regularly in the infant's diet. Regular and frequent exposure to a potential food allergen may help prevent the development of food allergies.
  • Healthcare providers should encourage parents/caregivers to monitor their children for any signs or symptoms of an allergic reaction, especially when introducing a priority allergen food. The signs and symptoms of an allergic reaction should be discussed with parents.
  • Breastfeeding infants require a vitamin D supplement of 400 international units (IU) daily. Optimal vitamin D status is important for healthy growth and development, but a vitamin D deficiency may also increase the risk of food allergies and increase severity of atopic dermatitis.6

How to support patients with food allergies

Date of creation: November 26, 2017
Last modified on: October 7, 2018


1Soller L et al. (2015). Adjusting for nonresponse bias corrects overestimates of food allergy prevalence. The Journal of Allergy and Clinical Immunology: In Practice 3(2):291-293.
2Canadian Paediatric Society and Canadian Society of Allergy and Clinical Immunology. (2016). Dietary exposures and allergy prevention in high-risk infants. Paediatr Child Health 18(10):545-9.
3Health Link BC. (2011). Eczema and Food Allergies in Babies and Young Children. Retrieved from
4Gupta RS et al. (2013). Factors associated with reported food allergy tolerance among US children. 111(3):194-198.
5Health Canada, Canadian Paediatric Society, Dietitians of Canada, and Breastfeeding Committee for Canada. (2015, August 18). Nutrition for Healthy Term Infants: Recommendations from Birth to Six Months. Retrieved from
6Baek JH et al. (2014). The link between serum vitamin D level, sensitization to food allergens, and the severity of atopic dermatitis in infancy. Journal of Pediatrics. 165(4):849-854.