According to Parents, babies should not eat eggs until they are 12 months old due to the possibility of egg white allergies. It is permissible to feed babies mashed hard-boiled egg yolks as early as 9 months of age.
Parents points out that some pediatricians advise avoiding eggs until babies are 2 years old, especially if there is a family history of allergies or asthma. Egg whites are one of the most common allergens. A child with an egg white allergy displays symptoms that can include flushing, hives, an increased heart rate, swelling and wheezing. Most children outgrow egg white allergies by the age of 5.