Many mothers do not understand how a child may be allergic to milk. It is not allergy to breast milk, but the protein primarily found in cow’s milk. A baby allergic to cow’s milk protein that is in exclusive breastfeeding may have symptoms of allergy if the mother consumes cow’s milk and its derivatives.The  reason is simple: the allergenic protein passes into breast milk and reaches the baby causing allergy.

Many mothers also often confuse milk allergy with lactose intolerance. They are different things, although having some similar symptoms. Lactose is a sugar that exists, in a natural way, in milk and to be digested in the human organism,needs a particular enzyme, the lactase, usually present in the intestinal mucosa. Sometimes the body has little (or none) of this enzyme, resulting in lactose intolerance.

The protein allergy involves principles quite different from lactose intolerance. There is no lactose allergy, because being sugar, lactose has no allergenicity. Several proteins can cause allergies, including milk, egg, wheat and peanuts, among others. Meanwhile the proteins of milk and egg are the ones causing major problems for young children.

Allergy to cow’s milk is an allergic reaction to proteins found in cow’s milk or their derivatives. This is because when babies are born, is intestine is still immature and the intake of these proteins can initiate a process of inflammation in the digestive tract. The cow’s milk allergy affects about 5% of babies and children under 3 years, as adults rarely have the disease.

Symptoms can occur immediately after ingestion of cow’s milk (immediate symptoms), or may take seven to ten days to appear (later symptoms, which are more frequent). The immediate symptoms are vomiting, wheezing or hives. Anaphylactic shock is rare. The symptoms may be delayed abdominal pain, vomiting, diarrhea, blood and mucus in the stools, colic, irritability or refuse to eat. This type of reaction is more difficult to diagnose, because it can also occur in situations other than cow’s milk allergy.

To make the diagnosis of the allergy cow’s milk protein, the story reported by the parents is crucial and directs the implementation of additional tests that help in diagnosis. Collecting the data you must have information about the list of suspect foods, route of exposure (oral, inhalation), interval between exposure and onset of symptoms, duration and specification of these symptoms, patient’s response to treatments and reproduction of the allergic whenever there is ingestion or inhalation of food.