Cow’s milk protein allergy and lactose intolerance are not the same.
Cow’s milk protein allergy (CMPA) and lactose intolerance are often confused with each other, but they are very different. 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?
Cow’s milk is made up of lots of different components such as proteins (casein and whey), milk sugar (called lactose) and fat.
An allergic reaction happens when the immune system mistakes the proteins in cow’s milk as a threat, when in fact they should be identified as harmless. The body then releases chemicals, including histamines, that trigger the signs and symptoms of an allergic reaction. This is why cow’s milk allergy can also be called cow’s milk protein allergy.
What triggers lactose intolerance?
In the case of lactose intolerance, the digestive system can’t fully break down and digest this milk sugar because it doesn’t make enough of the lactase enzyme. Instead of being broken down and absorbed, the lactose travels intact to the large bowel to be used as fuel for our gut bacteria. This can release gases that cause the symptoms of lactose intolerance.
Who has dairy issues?
Cow’s milk protein allergy tends to affect younger children under the age of 3 years. Most will grow out of this food allergy as they get older, often by the time they start school.
Only in very rare cases does lactose intolerance affect babies from birth (called congenital lactase deficiency). In this case, the person remains lactose intolerant for life.
What are the symptoms?
CMPA and lactose intolerance in babies can share some of the same signs and symptoms, including feeding and bowel problems such as:
- Bloated tummy
- Tummy aches and cramps
- Tummy rumbling
- Feeling nauseous
However, since cow’s milk protein allergy involves the immune system, babies who are allergic to cow’s milk protein may also show allergy symptoms like an itchy rash, wheezing, or runny noses and coughs. These aren’t seen in cases of lactose intolerance because that doesn’t involve the immune system.
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 symptoms.
How are they diagnosed?
There are different tests for CMPA and lactose intolerance, so it’s important to discuss your child’s symptoms in detail with their 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, he or she may request a hydrogen breath test, lactose tolerance test, milk tolerance test or stool sample.
It’s important that you don’t make any changes to your child’s diet without the supervision of a healthcare professional.
How are these conditions managed?
Since CMPA and lactose intolerance are caused by two different problems, there are slightly different ways of managing each condition.
Cow’s milk protein allergy 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 be managed by completely eliminating cow’s milk protein from the diet, too. An entirely dairy-free diet is rarely needed in the long term though, 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 babies may benefit from having a lactose-free infant formula.
In either case, it’s important that you don’t make any changes to your child’s diet without the supervision of a healthcare professional. Be sure to speak to your doctor if you’re concerned that your infant might have CMPA or lactose intolerance.