CMA is the most common food allergy in infants and children. It is so common because cow’s milk proteins are the first major food proteins formula-fed infants are confronted with. This can happen even if your child is exclusively breast-fed, because the mother’s diet has included milk or dairy products so that small amounts of cow’s milk proteins are passed on through her milk. So, also a breast-fed baby could develop CMA.
It is not clearly understood why some children’s immune system tries to fight one or more food proteins. In general, infants and young children are much more sensitive to these proteins as their immune systems are still quite immature. Children coming from a family with an extensive history of allergy, asthma, hives, hay fever, or eczema (parents or siblings) have a greater risk of developing food allergy than those with allergy-free relatives.
Still, about the half of food allergic babies have no family history of allergy at all. Be sure to mention this to your child’s doctor when he asks about the medical history of your child.
Fortunately, most children will grow out of food allergies like CMA. It is most common in the first 2 to 3 years of life, but then the symptoms may disappear completely as the child grows older.