Childhood allergies are an immune system overreaction where harmless substances, like food proteins, are mistakenly identified as a threat. The body responds by producing specific antibodies, leading to allergic symptoms upon exposure. The immune system matures and develops tolerance over time, making the question of whether a child will outgrow an allergy a common concern for parents. The likelihood of tolerance depends on factors including the specific food and individual biological characteristics.
Which Allergies are Commonly Outgrown
Childhood food allergies are categorized into two groups: those with high resolution rates and those that tend to be lifelong. Allergies to cow’s milk, egg, wheat, and soy are most likely to resolve spontaneously. Approximately 60 to 80 percent of young children with milk or egg allergies are able to tolerate the food by the time they reach their teenage years.
Resolution often occurs relatively early. Nearly 76 percent of children with an IgE-mediated milk allergy find resolution around age three. Egg allergy also shows high rates, with about 90 percent of affected children outgrowing the allergy by age six, and wheat allergy resolves in around 80 percent of children by age five.
In contrast, allergies to peanut, tree nuts, fish, and shellfish are generally more persistent and often lifelong conditions. Only about 20 to 25 percent of children with a peanut allergy eventually outgrow it. Resolution rates for tree nut allergies are lower, with estimates suggesting only about 14 percent resolve. Shellfish and fish allergies are the least likely to resolve, with rates in the range of 4 to 5 percent.
Predictors of Allergy Persistence or Resolution
The natural resolution of an allergy is not solely determined by the type of food, as individual factors significantly predict the outcome. One primary predictor is the level of allergen-specific Immunoglobulin E (IgE) antibodies in the blood. Higher initial levels of specific IgE are associated with a lower likelihood of resolution and indicate a more persistent allergic profile.
For example, a child with a lower egg-specific IgE level at diagnosis has a higher chance of outgrowing the allergy compared to a child with a very high level. The presence of other allergic conditions, known as comorbidities, also influences persistence. Children who have asthma or moderate to severe atopic dermatitis (eczema) may experience a slower rate of allergy resolution.
The initial severity of the allergic reaction is another variable; less severe reactions are associated with earlier resolution. The age when the allergy first appeared may also influence the course, with earlier onset sometimes resolving faster. Elevated total serum IgE levels in the blood, distinct from food-specific IgE, are also a factor linked to a longer duration of the required food elimination diet.
How Doctors Confirm Allergy Resolution
Confirming that a child has truly outgrown an allergy requires a formal medical evaluation, not just the absence of recent symptoms. The process begins with screening tests to monitor the decline of the immune response. These tools include the skin prick test and a blood test to measure food-specific IgE antibodies.
The skin prick test measures the size of the reaction wheal on the skin, while the blood test quantifies circulating IgE antibodies. A decrease in the skin prick test reaction size or a drop in specific IgE levels suggests tolerance is developing. However, a positive result only indicates sensitization—meaning the immune system is primed to react—but does not definitively confirm a clinical allergy.
The gold standard test for confirming allergy resolution is the Oral Food Challenge (OFC). This procedure is performed in a controlled medical setting, such as a clinic or hospital, where emergency equipment and trained personnel are available. During the OFC, the child is given gradually increasing amounts of the suspected allergen over several hours while being closely monitored. If the child successfully consumes the full dose without symptoms, the allergy is officially resolved, and the food can be safely reintroduced into the diet.