Common Childhood Food Allergies


Cow’s milk, egg and peanuts are responsible for most food-induced allergic reactions in children aged 1-3 years. Most children with food allergy are allergic to more than one food. Peanut, treenut, fish and shellfish are the most common food allergies in children aged >3 years1. In general children with milk or egg allergy are likely to outgrow them during childhood, whilst those with nut or fish allergies are likely to remain allergic into adulthood. The most common childhood food allergies are collectively known as “The Big 8”: milk, eggs, fish, shellfish, tree nuts, peanuts, wheat and soya.

Cow’s Milk Protein Allergy (CMA) is the most common food allergy of early childhood as it the main exposure that infants have with cohort studies estimating a rate of around 2-3%2, although this number may indeed be higher, considering the number of cases that go undiagnosed. For up-to-date evidence-based information regarding the diagnosis and management of CMA, please refer to the article on our website.

Egg allergy is the most common childhood allergy, with an estimated prevalence of 3% among Irish children3,4. It usually develops in infancy, with the introduction of egg in the weaning diet. Complete avoidance of egg is not routinely recommended. Raw or lightly cooked egg (e.g. scrambled egg, omelette, mayonnaise, meringues) is most allergenic with baked egg (buns, cake) less so.  Baked egg consumption may increase tolerance to lightly cooked eggs4.

Peanut allergy occurs in 2% of children3,4 and is the most common cause of nut allergy. Most children do not outgrow their allergy to peanuts, with peanut allergy eliciting more severe reactions compared to other food allergies. It is estimated that 80-90% of children with peanut allergy will have other atopic conditions4. Severe reactions tend to be seen with the ingestion of peanut, contact reaction can occur, however usually presents as mild symptoms4. Approximately 50% of peanut allergic children will develop an allergy to tree nuts4.

Any suspected case of peanut allergy must be referred to a specialist, with complete avoidance of peanut and any other nut not already consumed and tolerated, until assessed by a specialist.

Recent research has indicated that delaying the introduction of allergenic foods increases the risk of developing a food allergy in the infant or child during the avoidance period. The longer the avoidance period, the higher risk of allergy developing4.

Two significant studies, Learning Early about Peanut Allergy (LEAP), and Enquiring About Tolerance (EAT) study highlighted that by achieving early introduction of common food allergens, the development of allergy to these foods could in fact, be prevented in high risk groups4,5,6.

Allergens to introduce include peanut, egg, dairy, tree nut, fish and seafood. Both Irish (ICGP) and UK (BSACI) guidelines recommend that once weaning has commenced between 4-6 months, food allergens should be introduced into the weaning diet14. Each allergen should be introduced one at a time, so that if a reaction occurs, the allergen can be identified.  Once introduced, these foods should be included as part of their usual diet (i.e. several times per week and indefinitely).

  1. Food Allergy in Summary www.ifan.ie
  2. Luyet D et al, BSACI Guideline for the diagnosis and management of Cow’s Milk Allergy (2014) Clinical and experimental allergy 44:642-672
  3. Food Allergy in children and young people: Diagnosis and assessment of food allergy in children and young people in Primary Care and Community Settings (CG 116) National Institute for Health and Clinical Excellence (UK) 2010
  4. Irish College of General Practitioners Quick Reference Guide (ICGP QRG). Food Allergy in Children. Dublin: ICGP;2020 [cited 06 2020]. Available from URL: icgp.ie
  5. Du Toit G, Roberts G, Sayre PH, Bahnson HT, Radulovic S, Santos AF, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. N.Engl.J.Med. 2015 Feb 26; 372(9):803-813.
  6. Perkin MR, Logan K, Marrs T, Radulovic S, Craven J, Flohr C, et al. Enquiring About Tolerance (EAT) study: Feasibility of an early allergenic food introduction regimen. J.Allergy Clin.Immunol. 2016 May; 137(5):1477 1486.e8.