My 4-year-old son is allergic to both peanuts and eggs. Is it possible he will outgrow these allergies as he gets older?

Answers from James T C Li, M.D., Ph.D.

Eight foods trigger 90 percent of all food allergies. Peanuts and eggs are two of them. The rest are milk, fish, shellfish, tree nuts, soy and wheat.

Statistically speaking, there's a good chance he can safely eat eggs as an adult. Children usually outgrow egg and milk allergies as they get older.

Unfortunately, it's much less likely for him to outgrow his peanut allergy. By school-age, this allergy is resolved in only 20 percent of children. Peanut consumption remains a common cause of allergic reactions in adults.

Your son can outgrow his food allergies if and when his body begins to suppress the production of a protein called immunoglobulin E (IgE). The immune system releases this protein when it mistakenly identifies a food substance, such as peanuts and eggs, as something harmful. IgE suppression is key to gaining tolerance for foods that have previously caused an allergic reaction.

There are other factors that can affect the likelihood of your son outgrowing his allergies. These include the severity of his reactions, how many foods he's allergic to, and how old he was when he had his first reaction.

Mar. 04, 2014