One of the first proteins that an infant eats are the proteins in cow's milk. Milk proteins are also one of the most common food allergies that affect infants, writes Dr. Michael Levin in the November 2005 issue of "Pediatrics." Some of the infants who are allergic to the proteins in cow's milk may even be allergic to soy proteins as well.
Statistics
Approximately 0.5 to 1.0 percent of infants have a milk protein allergy or intolerance, according to Dr. Judith Sondheimer in "Current Diagnosis & Treatment: Pediatrics." Intolerance to milk proteins is more common in male infants than in female infants. Protein allergy is also more common in those infants who have a family history of allergies.
Symptoms
Some physicians prefer the term "protein intolerance" instead of "protein allergy" to ensure they are including all of the reactions to food proteins and not just the allergic reactions. Most infants with a milk protein allergy have symptoms that include diarrhea, vomiting and colic. Dr. Sondheimer writes in "Current Diagnosis & Treatment: Pediatrics" that, many times, the infants will also have a little bit of mucus and blood in their bowel movements. These infants are otherwise healthy and gain the normal amount of weight.
Treatment
Women who are breastfeeding do not need to stop. They should stop drinking whole milk because the protein transfers to human milk. For infants taking formula, switching to soy formula usually helps. Otherwise, infants can drink a hydrolysate formula. This formula is based on cow's milk, but the carbohydrates, proteins and fats are smaller and should not cause an allergic response, according to Dr. Eve Colson in "The Merck Manual for Healthcare Professionals." In elemental formulas, the proteins are broken down to amino acids.
Outcome
The symptoms usually improve when women who are breastfeeding stop drinking whole milk. Infants on formula get better when they are switched to a different formula. In "Current Diagnosis & Treatment: Pediatrics," Dr. Sondheimer writes that for those infants who have allergic colitis, this disorder will usually clear up on its own within six months to a year. Allergic colitis is the inflammation of the colon due to allergies. These infants will have diarrhea, large lymph nodes near the rectum and swollen membrane in the colon.
Complications
Dr. Sondheimer writes that an anaphylactic reaction associated with IgE antibodies is a very rare, life-threatening complication. IgE antibodies are on the surfaces of the basophil and eosinophil white blood cells and on the mast cells. If a foreign substance, called an antigen, attaches to these antibodies, the antibodies will trigger the cells to release substances to destroy that antigen. In this type of anaphylactic reaction, a foreign milk protein is seen as an antigen. The infant can quickly become pale, vomit and develop very low blood pressure.
References
- "Current Diagnosis & Treatment: Pediatrics"; William Hay, Jr., M.D., Myron Levin, M.D., Judith Sondheimer, M.D., Robin Deterding, M.D.; 2009
- The Merck Manual for Healthcare Professionals: Nutrition in Infants
- Pediatrics: Anaphylaxis in a Milk-Allergic Child After Ingestion of Soy Formula Cross-contaminated With Cow's Milk Protein
