Two million — or 8 percent — of children in the United States are affected by food allergies. Common food allergies in kids include milk, eggs, soy, wheat, peanuts and tree nuts. Cow milk allergies can affect people of any age, but it is more common among infants. About 2 to 3 percent of infants have a cow milk allergy, though most typically outgrow it.

Casein and whey, which are the main proteins in cow milk, can cause allergic reactions in babies with a genetic predisposition. When those babies are exposed to cow milk, they could develop IgE antibodies that trigger allergic reactions. It can occur immediately or take up to several days after milk ingestion. Symptoms include hives, eczema, facial swelling, vomiting, diarrhea or wheezing. Severe reactions occur rarely but can result in anaphylaxis.

Lactose intolerance is a different form of cow milk allergy and is rare in infants. It is more common among older kids and adults. Lactose intolerance does not involve our immune system. It is due to the lack of a specific enzyme to digest sugar lactose. Small amounts of cow milk are usually tolerated. Except for skin rash and wheezing, other symptoms are quite similar to those of cow milk allergy, such as diarrhea, vomiting and abdominal pain.

If your baby has a cow milk allergy, goat milk is not a good alternative as it contains some proteins similar to those in cow milk. You may be advised to switch to a soy protein-based formula. Because it has no milk sugar (lactose), it is also used by people who are lactose intolerant. Unfortunately, around 20 percent of cow milk-allergic children are also allergic to soy milk.

If your infant can’t tolerate soy, you may have to switch to a hypoallergenic formula. Extensively hydrolyzed formulas have cow’s milk proteins that are broken down into small particles so that they are less allergenic than the whole proteins in regular formulas. Most infants who have a milk allergy can tolerate these formulas, but in some cases they still can provoke allergic reactions. In that case, amino acid-based infant formulas, containing protein in its simplest form, are recommended. Partially hydrolyzed formulas, not considered truly hypoallergenic, are not recommended for a baby with a cow milk allergy.

Breast milk is the best form of nutrition for neonates and infants. The American Academy of Pediatrics recommends the mother should continue breast feeding their infants for at least 6 months if possible. Though there is no conclusive evidence that breast feeding can prevent allergies from developing later in your child’s life, it does however delay the development of food allergies by postponing your infant’s exposure to those foods that can potentially cause allergies.