Cow’s milk protein allergy (CMPA) is a very common food allergy that mainly affects children, but some adults, too.

It occurs when the body’s immune system reacts abnormally to one or more of the proteins found in cow’s milk.

This immune reaction triggers a number of symptoms that can range from mild to severe. While CMPA often develops in early childhood, many children outgrow it by the age of 3 or 4 years old.

Understanding the causes, symptoms, diagnosis, and treatment options for CMPA is important for properly managing this condition.

If you think your child may have CMPA, you can book an appointment to see me in clinic.

Overview of CMPA

Cow’s milk protein allergy is an abnormal immune reaction to the proteins in cow’s milk, triggered by the body’s immune system mistaking them as harmful. The body then releases chemicals like histamine to defend against the “invader,” causing the symptoms of an allergic reaction.

Cow’s milk protein is one of the most common food allergens in infants and young children, affecting somewhere between 1.8% – 7% of babies and children. While many outgrow it, CMPA persists in a smaller subset into adulthood. The condition can range from mild to severe and life-threatening in rare cases. Strict avoidance of cow’s milk protein is the most effective way to prevent reactions.


Patient’s parent via Doctify, for CMPA/Food allergies

““Dr Mathur has been excellent in treating my daughter’s reflux and CMPA. He spent a great deal of time understanding her history and has always been willing to hear our concerns.”


The signs and symptoms of cow’s milk protein allergy can occur minutes to hours after consuming cow’s milk and may include:

  • Skin reactions: hives, swelling, itching, eczema flare-ups, cradle cap
  • Gastrointestinal issues: vomiting, diarrhoea, abdominal pain, colic, bloody stool
  • Constipation
  • Reflux
  • Respiratory problems: runny nose, sneezing, coughing, wheezing
  • Oral allergy symptoms: itchy mouth, throat, tongue or lips

Symptoms can be mild to severe and life-threatening in some cases.


Cow’s milk protein allergy is caused by a malfunction with the immune system. Normally, the immune system can tell the difference between harmful foreign invaders like bacteria and viruses vs. harmless proteins.

In CMPA, the immune system mistakenly sees cow’s milk proteins as a threat and releases antibodies and chemicals like histamine to defend the body against them, triggering an allergic reaction.

Both genetic and environmental factors likely play a role. A child with a close relative with allergies is at higher risk, for example. Environmental exposures also influence immune system development early in life, but more research is required within CMPA.


CMPA can be tricky to diagnose, as symptoms may be vague and overlap with other conditions like gastroesophageal reflux disease and Pyloric stenosis.

I will usually begin by taking a full medical history, allergy history, and undertake a physical exam.

I then may recommend:

  • Blood test: Checking antibody levels to milk proteins
  • Elimination diet: Removing dairy from the diet for 2-4 weeks to see if symptoms improve
  • Giving dairy under my medical supervision to confirm a reaction
  • Patch test: Putting a tiny amount of milk protein on the skin to check for a reaction

Identifying exactly which protein triggers the allergy can help guide treatment and management.


The most effective treatment is complete avoidance of cow’s milk protein. Reading ingredient labels carefully and avoiding cross-contamination is key. Options may include:

  • Breastfeeding: If mother excludes dairy from her own diet*
  • Extensively hydrolysed formula: Proteins are broken into smaller parts less likely to trigger allergy
  • Amino acid formula: a hypoallergenic amino acid formula
  • Plant based formulas: like Oat, coconut or almond
  • Nutritionist support: To ensure adequate nutrition if avoiding major food groups

*This should only be done after discussion with a Registered Dietitian, as it is important that breast-feeding mums eat a healthy balanced diet. Suitable supplements may be required.

For mild reactions, antihistamines may help manage symptoms. Epinephrine auto-injectors are prescribed for severe reactions. Immunotherapy is being studied but not ready for clinical use.

Many children outgrow CMPA over time.

Lifestyle Changes

Living with CMPA requires vigilance in avoiding cow’s milk proteins. This may mean:

  • Reading every label carefully when grocery shopping
  • Calling manufacturers to ask about shared equipment with dairy
  • Carrying epinephrine if prescribed
  • Alerting caregivers, schools, etc. about allergy and emergency plan
  • Frequently cleaning surfaces and avoiding cross-contamination
  • Planning safe snacks/meals when traveling or eating out
  • Working with a Registered Dietitian to ensure proper nutrition
  • Having alternatives (safe non-dairy milk, cheese, butter, etc.) on-hand

Support Resources

Being the parent of a child with food allergies like CMPA can feel isolating, but support is available:

  • Paediatricians and allergists: Help create a management plan and answer questions
  • Peer support groups: Connect with others managing CMPA for their child/ren
  • Mental health professional: Cope with anxiety, fear, depression
  • Dietitian: Ensure proper nutrition while avoiding major food groups
  • Online resources: Recipes, product recommendations, latest research

Knowing where to turn for support can make the journey easier for those living with CMPA.

Frequently Asked Questions

Can I breastfeed if my child has CMPA?

Yes, you can still breastfeed by fully excluding dairy proteins from your own diet. Always consult a Registered Dietitian.

Will my child outgrow CMPA?

About 80-90% will outgrow it by age 3 or 4. But it can persist into adulthood for the remaining 10-20%, specially if they have IgE mediated CMPA.

What are some safe milk substitutes?

Rice, oat, soy, potato, coconut, hemp, and almond milk can be safe alternatives. Always check labels and consult with a Paediatrician and a Registered Dietician.

Is CMPA the same as lactose intolerance?

Lactose intolerance is not an allergy but rather an inability to digest milk sugar. Those with CMPA are allergic to the milk proteins, not the sugar.

Can my child still eat dairy products like cheese or yogurt?

No, all dairy products including cheese, yogurt, butter, ghee etc. must be strictly avoided to prevent an allergic reaction.


Cow’s milk protein allergy is a common food allergy triggered by an abnormal immune reaction to milk proteins. Avoiding cow’s milk protein through careful label reading, wise substitutions, and carrying epinephrine (where prescribed) can help you manage the condition.

I’ll work with you to accurately diagnose CMPA in your baby, and if so, provide advice and recommendations to help you manage it.