- Milk allergy symptoms can develop in both formula-fed and bottle-fed babies. Formula-fed babies drink cow's milk directly, since it provides the basis of most commercial baby formulas, so these babies are much more likely to develop a milk allergy and the symptoms that accompany it. However, even if you exclusively breastfeed your baby, he may react to the small amount of milk protein that comes from your diet and enters your supply of breast milk. In addition, some breast-fed babies develop sensitivity to the cow's milk protein in their mothers' diets, but they don't start developing milk allergy symptoms until they drink cow's milk directly.
- Your baby may develop certain symptoms within moments of exposure to cow's milk. Such symptoms include irritability, wheezing, vomiting, hives and bloody diarrhea. These more immediate symptoms are less likely to occur than slower onset symptoms, which your baby can experience seven to 10 days after exposure to cow's milk, according to KidsHealth.org. These more common symptoms include diarrhea (possibly with blood), abdominal cramps, vomiting, coughing, gagging, runny nose, skin rash and colic.
- In rare instances, your baby may exhibit anaphylaxis, a life-threatening allergic reaction that restricts breathing and blood circulation. Anaphylaxis typically occurs within moments of your baby's exposure to cow's milk. Accompanied by airway constriction, dizziness, a rapid pulse and a drop in blood pressure, anaphylaxis requires immediate epinephrine treatment. If you suspect that your baby is having an anaphylactic reaction, call 911 and take her immediately to the emergency room for diagnosis and treatment.
- If you think your baby has milk allergy symptoms, talk to your doctor about testing. Since milk allergy symptoms are similar to the symptoms of many other ailments in babies, getting your doctor involved as soon as possible helps you find out if a milk allergy is the cause. Your doctor will assess your baby's symptoms and provide testing and follow-up care as needed, as well as a referral to an allergist. According to KidsHealth.org, common tests include allergy skin tests in which a small portion of the milk protein is injected under the skin; a resulting raised spot, or wheal, indicates an allergy to milk.
- Milk allergies in babies are different than lactose intolerance. Lactose intolerance, which occurs rarely in babies, happens when your baby has an intolerance to the lactose sugar in cow's milk; the baby's body lacks an enzyme called lactase that breaks down the sugar. True milk allergies, which are much more common in babies, take place when a baby's body reacts to the casein protein and whey protein in milk. Symptoms of lactose intolerance in babies typically include digestive problems such as gas, cramps, and diarrhea. According to the American Academy of Pediatrics, babies outgrow 80 to 90 percent of milk allergies by their fifth year.
