Skip to Main Content
CMA or Lactose Intolerance?

CMPA or Lactose Intolerance?

Cow’s milk protein allergy (CMPA) and lactose intolerance have similar indicators but are not the same condition.

Cow’s milk protein allergy (CMPA) is one of the most common types of food allergy in infants and is the immune system overreacting to one or more proteins found in cow’s milk. Lactose intolerance is the body’s inability to digest lactose, which is a natural sugar in milk. Both can cause similar and unpleasant experiences, and can be relieved with simple dietary adjustments.

If you suspect your baby may have an issue with dairy and are trying to figure out whether it’s CMPA or lactose intolerance, it’s important to learn what sets them apart so you can have an informed conversation with your pediatrician.

What triggers CMPA or lactose intolerance?

Cow’s milk is made up of lots of different components, such as proteins (casein and whey), milk sugar (lactose), and fat which are all important for helping babies grow. A cow’s milk protein allergic reaction happens when the immune system mistakes the proteins in cow’s milk as a threat when they should be identified as harmless. The body thinks it has an invader, so it responds in ways that can make your little one feel sick and uncomfortable.

In the case of lactose intolerance, the digestive system can’t fully break down and digest the milk sugar because it doesn’t make enough of the lactase enzyme. Instead of getting broken down and absorbed, the lactose travels intact to the large bowel to be gobbled up by bacteria that live in the gut. This can cause gas to build up in the gut and other digestive issues, and ultimately lead to gassiness and stool issues.

Lactose intolerance that affects babies from birth is called congenital lactase deficiency. While lactose intolerance is uncommon in babies, it is possible for babies to experience lactose sensitivity for a short time after illness or antibiotics.

When it comes to CMPA, even a small amount of cow’s milk protein could give your baby an allergic reaction. With lactose intolerance, babies can typically tolerate small amounts of milk products without noticing any issues–and they may become more intolerant with age as the amount of lactase in their intestines decreases naturally.

It's important to note that cow’s milk protein allergy tends to affect younger children under three. Most will grow out of this food allergy as they get older, often by the time they start school.

Indicators associated with CMPA

CMPA and lactose intolerance in babies can share some of the same indicators, including:

  • Gas
  • Diarrhea
  • Bloated tummy
  • Tummy aches and cramps
  • Tummy rumbling
  • Feeling nauseous

However, since CMPA allergy involves the immune system, babies who are allergic to cow’s milk protein may also show CMPA indicators such as:

  • Itchy rash
  • Wheezing
  • Runny nose
  • Cough
  • Flushed face
  • Watery eyes

Indicators associated with lactose intolerance

The most common lactose intolerance indicators in babies include:

  • Diarrhea
  • Vomiting
  • Excess gas

How are CMPA and lactose intolerance diagnosed?

A variety of tests and evaluations can be used by a qualified medical professional to diagnose CMPA and lactose intolerance. It’s important to discuss your baby’s experiences in detail with your pediatrician, who will decide which tests are most appropriate.

If cow’s milk protein allergy is suspected, your doctor may request an allergy test, such as a skin prick test or blood test, and/or advise you to put your baby on an elimination diet followed by a food challenge.

If your doctor thinks it may be lactose intolerance, they may request a hydrogen breath test, lactose tolerance test, milk tolerance test, or stool sample.

It’s important to avoid making any changes to your child’s diet without the supervision of a healthcare professional.

How to manage milk intolerance or CMPA in infants

Since CMPA and lactose intolerance are caused by two different problems, there are slightly different ways of managing each condition.

CMPA is managed by completely eliminating cow’s milk protein from your baby’s diet because even a small amount of cow’s milk protein could potentially trigger an allergic reaction.

Lactose intolerance may also be managed by completely eliminating cow’s milk protein from the diet. An entirely dairy-free diet is rarely needed long term, except for infants diagnosed with galactosemia who must avoid lactose and require a specialized formula. In most lactose intolerance cases, dairy products can be carefully reintroduced into the diet with the careful guidance of a doctor. Some formula-fed babies may benefit from switching to a formula designed for little ones with sensitive tummies, such as the easy-to-digest Enfamil Sensitive formula or Enfamil’s plant-based, non-dairy formula, ProSobee.

In either case, avoid changing your child’s diet without talking to your doctor first. Make an appointment with your pediatrician if you’re concerned that your infant might have CMPA or lactose intolerance.

When to talk to a pediatrician

If your baby is having any problems with feeding, isn't putting on weight, or is showing any other issues or indicators you are concerned about, go to your pediatrician. They can help figure out what the underlying issue is and help resolve it. And if your baby has been diagnosed with cow's milk allergy, ask your doctor about Nutramigen, Enfamil’s special formula for infants with CMA. Parents of infants who have lactose intolerance or are sensitive to dairy products may want to inquire about how Enfamil Sensitive and ProSobee infant formulas can help manage and soothe tummy issues and fussiness.

All information on Enfamil, including but not limited to information about health, medical conditions, and nutrition, is intended for your general knowledge and is not a substitute for a healthcare professional's medical identification, advice, or management for specific medical conditions. You should seek medical care and consult your doctor or pediatrician for any specific health or nutrition issues. Never disregard professional medical advice or delay seeking medical treatment, care, or help because of information you have read on Enfamil.