CMPA vs Lactose Intolerance: What’s the Difference?

CMPA and lactose intolerance are often confused because both involve milk and can cause digestive symptoms. They are not the same condition.

CMPA is an allergy to milk protein

Cow’s milk protein allergy involves the immune system reacting to proteins in cow’s milk. Symptoms can affect more than the digestive system and may include skin or respiratory symptoms as well as vomiting or bowel changes.

Lactose intolerance involves milk sugar

Lactose intolerance happens when the body cannot digest lactose, the sugar naturally found in milk. NHS guidance notes that it is rare in babies. Typical symptoms are digestive, such as diarrhoea, abdominal discomfort, wind and bloating.

Why does the difference matter?

A lactose-free product can still contain cow’s milk protein, so it is not automatically suitable for someone with CMPA. Likewise, the assessment and feeding advice for CMPA is different from the approach used for lactose intolerance.

What about formula?

NHS guidance states that lactose-free formula is intended for lactose intolerance under medical supervision, while babies diagnosed with cow’s milk allergy may be prescribed an appropriate hypoallergenic formula. Partially hydrolysed comfort formula is not suitable for cow’s milk allergy.

Do not self-diagnose from symptoms alone

Because digestive symptoms can have many causes, speak to a GP, health visitor, paediatrician or dietitian if you are concerned about your baby or child.

Next: Read What Is CMPA? and visit our Symptoms & Diagnosis section.

Sources

NHS: Types of formula milk. Cambridge University Hospitals: Milk allergy.

MilkPath provides general information and parent support, not individual medical advice. Always seek personalised guidance from an appropriate healthcare professional.