When describing my 3-year old’s food allergies as an infant, people immediately want to know how she is doing today. Luckily, she went from severe reactions to completely food tolerant by the time she was one. Interestingly, it is not uncommon for infants to essentially “grow out” of their food sensitivities.
Approximately 80% of food allergies occur before a person’s first birthday. Most of those cases resolve themselves within 9-12 months of the original allergy in infants . This is dependent on the individual child and the specific food causing the reaction. More specifically, children who are allergic to milk typically outgrow their intolerance while those with peanut and tree nut allergies do not. Even individuals who develop a tolerance for milk may do so in a few months while others may take 10 years.
Let’s Dig into the Data
One study examined 1749 infants, 117 had suspected milk allergy and 39 had confirmed cases. In the confirmed cases, 56% were milk tolerant by age 1, 77% by age 2, and 87% by age 3. This, and several similar research papers, support the concept that food sensitivities peak in the first year of age with varying levels of resolution by age three .
Another peer-reviewed article followed 82 food-allergic children from 6 months to 14 years old. Of the 12 children with milk allergies, only 1 remained unchanged by the end of their study. Of the 55 patients with egg allergies, only 11 remained unchanged. However, 27 of the 32 children with fish sensitivities and 35 of 35 children allergic to peanuts remained unchanged .
A smaller study found the following tolerance developments over time: 30% of egg, 57% of milk, 25% of wheat, and 67% of soy .
Interesting Facts 
Suspected food allergies are extremely common in early childhood, with 25% of parents reporting adverse food reactions. However, testing mechanisms for children under 1 year are inefficient and often inconclusive. This means that a mere 5-10% of infant food allergies are confirmed.
Children who suffer from one food allergy have a high risk of developing additional sensitivities to food as well as an increased risk of asthma and rhinitis.
Siblings of allergen-ridden children are significantly more likely to develop food allergies as well (which is why we were not surprised to discover that our second daughter also has food sensitivities).
Strict avoidance of the offending food helps the outgrowing process. Even small exposure to the food may delay the development of tolerance.
Infants who are found to have food allergies may develop a tolerance over time. The likelihood of this is dependent on the child and the offending food. To help the process, strict avoidance of that food is recommended for a minimum of several months.
Bock SA. Prospective appraisal of complaints of adverse reactions to foods in children during the first 3 years of life. Pediatrics.1987;79 :683– 688
Host A, Halken S. A prospective study of cow milk allergy in Danish infants during the first 3 years of life. Clinical course in relation to clinical and immunological type of hypersensitivity reaction. Allergy.1990;45 :587– 596
Dannaeus A, Inganas M. A follow-up study of children with food allergy. Clinical course in relation to serum IgE- and IgG-antibody levels to milk, egg, and fish. Clin Allergy.1981;11 :533– 539
Sampson HA, Scanlon SM. Natural history of food hypersensitivity in children with atopic dermatitis. J Pediatr.1989;115 :23– 27
Wood RA. The natural history of food allergy. Pediatrics. 2003 Jun 1;111(Supplement 3):1631-7.