What should I do if I think my baby is allergic or intolerant to cows' milk?

If you think your baby is having a reaction to cows' milk, see your GP to discuss your concerns.

They will be able to assess if your baby's symptoms may be caused by a cows' milk allergy or something else. Make sure you get medical advice before taking cows' milk out of your child's diet as it contains important nutrients.

Cows' milk allergy in babies

Cows' milk allergy (CMA), also called cows' milk protein allergy, is one of the most common childhood food allergies. It is estimated to affect between 2% and 7.5% of babies under one, though most children grow out of it by the age of five.

CMA typically develops when cows' milk is first introduced into your baby's diet either in formula or when your baby starts eating solids.

More rarely, it can affect babies who are exclusively breastfed because of cows' milk from the mother's diet passing to the baby through breast milk.

There are two main types of CMA:

  • immediate CMA – where symptoms typically begin within minutes of having cows' milk
  • delayed CMA – where symptoms typically begin several hours, or even days, after having cows' milk

Symptoms of cows' milk allergy

Cows' milk allergy can cause a wide range of symptoms, including:

  • skin reactions – such as a red itchy rash or swelling of the lips, face and around the eyes
  • digestive problems – such as stomach ache, vomiting, colic, diarrhoea or constipation
  • hayfever-like symptoms – such as a runny or blocked nose
  • eczema that doesn't improve with treatment

Occasionally CMA can cause severe allergic symptoms that come on suddenly, such as swelling in the mouth or throat, wheezing, cough, shortness of breath, and difficult, noisy breathing.

A severe allergic reaction, or anaphylaxis, is a medical emergency – call 999 or go immediately to your local hospital A&E department.

Treatment for CMA

If your baby is diagnosed with CMA, you'll be offered advice by your GP or an allergy specialist on how to manage their allergy. You may also be referred to a dietitian.

Treatment involves removing all cows' milk from your child's diet for a period of time. 

If your baby is formula-fed, your GP can prescribe special infant formula.

Don't give your child any other type of milk without first getting medical advice.

If your baby is exclusively breastfed, the mother will be advised to avoid all cows' milk products.

Your child should be assessed every 6 to 12 months to see if they have grown out of their allergy.

Read more about cows' milk allergy on the Allergy UK website.

Could it be lactose intolerance?

Lactose intolerance is another type of reaction to milk, when the body can't digest lactose, a natural sugar found in milk. However, this is not an allergy.

Lactose intolerance can be temporary – for example, it can come on for a few days or weeks after a tummy bug.

Symptoms of lactose intolerance include:

  • diarrhoea 
  • vomiting
  • stomach rumbling and pains
  • wind

Treatment for lactose intolerance

Treatment depends on the extent of your child's intolerance. Some children with lactose intolerance may be able to have small amounts of dairy products without having symptoms.

Your child may be referred to a dietitian for specialist advice.

Read more about treatment for lactose intolerance in children.

Further information:

Page last reviewed: 13/07/2016

Next review due: 13/07/2019