Many a new mom dealing with a fussy newborn (and truthfully, what newborn isn’t fussy?), has suspected that her suffering sweetheart must have a cow's milk allergy or intolerance, especially when well-intentioned friends and relatives are also blaming milk.
If you're breastfeeding or exclusively pumping, you may assume it’s the dairy in your diet that’s causing your little one to wail; if you’re formula feeding, you assume it’s the cow’s milk in the infant formula that’s causing the trouble.
Although it is one of the more common allergies in infants, milk allergies still only affect an estimated 2 to 3 percent of babies.[1] Confusing the issue further is that many people are unaware of the differences between a milk allergy, an intolerance to milk and lactose intolerance.
To clear up the confusion, here’s the breakdown on milk allergies and intolerance in breastfed and formula-fed babies.
What's the difference between milk allergies vs. lactose intolerance?
Milk allergy
With a true milk allergy in infants, a baby’s immune system reacts negatively to the proteins in cow’s milk. Breastfed babies are reacting to the dairy his mother has eaten (the milk proteins pass through breast milk), while formula-fed babies are reacting to the cow’s milk proteins in the formula.[2] In either case, a baby's immune system sees the cow’s milk proteins as foreign substances.
Milk intolerance
Milk intolerance, on the other hand, has nothing to do with cow’s milk proteins or the immune system, and instead has to do with the digestive system. Your child might have loose stools or blood in stool hours or days later.
Congenital lactose intolerance is an extremely rare metabolic condition that also impacts the digestive system. Lactose intolerance (lactose is a sugar found in dairy products) more commonly develops in older kids and adults. The few babies with lactose intolerance will usually fare much better on a formula with little or no lactose.[3]
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What are the symptoms of milk allergies in babies?
In its efforts to fend off the invaders, the body releases histamine and other chemicals, which cause allergic symptoms in the body.
Symptoms of milk allergies in babies include:[4]
- Frequent spitting up
- Vomiting
- Signs of abdominal pain, or colic-like symptoms, such as excessive crying and irritability (especially after feedings)
- Diarrhea
- Blood in stool
- Hives
- A scaly skin rash
- Coughing or wheezing
- Watery eyes and stuffy nose
- Trouble breathing or a bluish skin color
- Swelling (especially of the mouth and throat)
What are the symptoms of lactose intolerance in babies?
Symptoms of lactose intolerance in babies include:
- Gas
- Diarrhea
- Bloated stomach
- Spitting up
- Irritability, crying or other colic symptoms
- Failure to thrive and gain weight
How is a milk allergy in infants diagnosed?
If your baby has symptoms of either a milk allergy or milk intolerance, see your pediatrician. He or she will probably check for both with a physical exam, an examination of your baby’s stool, a discussion your family's history of allergies and/or a skin-prick test.
If your doc thinks your baby may have a milk allergy or intolerance, then you’ll probably be asked to eliminate milk from your diet (if you’re breastfeeding) or switch to a different formula (more on that below) to see whether your newborn’s symptoms improve.
After your baby has been cow’s-milk-free for about a week, the doctor may have you reintroduce cow’s milk to see whether your little one has a reaction to it.
How is a milk allergy in babies treated?
If it turns out that your newborn is one of the 2 to 3 percent of babies who has a milk allergy, don’t despair. Many children outgrow a milk allergy by the time they're around 1 year old, and the majority of babies with milk allergies outgrow the condition by about age 3.
In the meantime, your child's doctor may recommend the following:
- If your baby is formula-fed: Your pediatrician will suggest switching to a different formula. Because many babies with milk allergies are also allergic to soy (and to goat’s milk), the doctor may suggest a hypoallergenic formula with hydrolysate protein, which has milk proteins that are already partly broken down, so it’s less likely to cause a reaction.
- If you’re breastfeeding or exclusively pumping: Your pediatrician will likely recommend that you ditch dairy in your diet to see whether that makes a difference to your baby. Of course, making a major change to your diet is probably the last thing you want to think about when dealing with a fussy newborn, but it may very well resolve the issue. If you do eliminate dairy, be sure to talk with your doctor about how to make sure you’re still getting enough calcium and other nutrients in your diet.
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