Breast-feeding children for at least 4 months or more may help prevent atopic dermatitis cow milk allergy, and wheezing in early childhood.

However, changing a mother's diet during pregnancy or while breast-feeding does not seem to help prevent allergy-related conditions.

For most children, changing diet or special formulas does not seem to prevent these problems. If there is a family history of eczema and allergies in a parent, brother, or sister, discuss the infant feeding with your child's doctor. The timing of introduction of solid foods in general, as well as use of several specific foods, can help prevent some allergies.

There is also evidence that infants exposed to certain airborne allergens (such as dust mites and cat dander) may be less likely to develop related allergies. This is called the "hygiene hypothesis" and sprang from observations that infants on farms tend to have fewer allergies than those who grow up in environments that are more sterile.

Once allergies have developed, treating the allergies and carefully avoiding those things that cause reactions can prevent allergies in the future.