Mary, a 28-year-old schoolteacher with a history of hay fever and atopic dermatitis, is eight months pregnant. Her husband also has had asthma since childhood. They are wondering if there is any way to delay or even prevent their baby from developing allergies.

People with atopy have a tendency to develop closely linked allergic disorders — atopic dermatitis, hay fever and asthma. These patients have a genetic predisposition to produce IgE antibodies to allergens and trigger inflammation, leading to different allergic symptoms. Such disorders frequently run in families. Therefore, infants or children with a family history of asthma, hay fever or atopic dermatitis are at risk of developing allergic disorders.

In general, newborn infants are more likely to become allergic to foods than older infants. The way to prevent or delay a food allergy is to delay exposure to potential food allergens at an early age. Mothers should breast-feed their infants for at least six months if possible, since breast milk is much less likely to produce an allergic reaction and can strengthen the child’s immune system and decrease respiratory infection. Infants not being breast-fed should be fed with a hypoallergenic formula.

Infants should not be fed solid foods until they are 6 months old. When infants are 6 to 12 months old, vegetables, rice, meat, and fruit can be introduced to their diets. After the child is 1 year old, milk, wheat, corn, citrus and soy may be added. At 2 years of age, the child may have eggs. Finally, at age 3, fish and peanuts may be introduced.

As with food allergies, reducing contact with inhaled allergens, particular dust mites and cats, early in life may delay the onset of hay fever or asthma symptoms. The steps to reducing dust mite and animal dander include using zippered, plastic covers on pillows and mattresses and washing bedding in hot water every seven to 10 days. Indoor relative humidity should be kept below 50 percent and, optimally, carpets and upholstered furniture should be removed from the infant’s bedroom.

Also, avoid placing very young children in group day care to decrease their exposure to respiratory infections that can trigger asthma. Maternal smoking during pregnancy is associated with increased wheezing during infancy. Exposing children to secondhand smoke also can trigger asthma. Therefore, it is extremely important that infants not be exposed to tobacco smoke before or after they are born.

Although allergic disorders cannot be cured, by delaying exposure to allergens we may be able to postpone or even prevent the development of allergic disorders in children at an early age.