Firstly, what are food allergies? Food allergies occur when the body's immune system (the body's own defense mechanism) responds abnormally to certain foods.

For people with food allergies, the immune system incorrectly identifies certain food components as harmful and produces an inappropriate response. This leads to an unpleasant and on occasions life threatening signs and symptoms associated with allergies.

Cows’ milk allergy (CMA), also known as cows’ milk protein allergy (CMPA), is one of the most common food allergies in babies, and usually appears before 1 years of age.

What is CMPA?

CMPA is a type of milk allergy where a baby's immune system responds to the proteins found in cows’ milk, mistaking it for a harmful substance and attacks it, causing the baby to have allergic symptoms. These can include problems with the skin (rash, hives, dry, scaly or itchy skin), digestive system (diarrhoea, vomiting, constipation and reflux) and respiratory system (noisy breathing, coughing, runny nose). CMA usually occurs before a baby’s first birthday.

How common is CMPA and who is at risk?

2-3% of babies under the age of one years old suffer with CMPA. As children get older, the risk decreases.

If a parent or sibling has an allergic disease such as asthma, eczema, or any seasonal allergies, then the risk of developing CMPA is increased. There's evidence to suggest breastfeeding protects babies from developing CMPA.

Infographic of CMA

Signs and symptoms of CMPA

Cow’s milk protein allergy (CMPA), also known as cow’s milk allergy (CMA), is a common food allergy (or dairy allergy).

With such a wide range of symptoms, recognising CMPA can be a challenge. It is particularly difficult when symptoms are similar to the expected behaviour of your baby or when they overlap with other common problems.

Babies with CMPA may experience the following symptoms:

  • Digestive problems (such as diarrhoea, vomiting, constipation and reflux)
  • Skin problems (such as urticaria, hives and eczema)
  • Respiratory symptoms (such as persistent cough and wheezing)
  • Generic symptoms (such as tiredness, problems sleeping or crying)

It is also important to note that not all symptoms will occur immediately (within 2 hours) after feeding; some may be delayed by up to 2 days or even a week.

We understand that the symptoms can be distressing, particularly at this time when you are getting to know your baby. CMPA can be easily managed with the correct diet, so getting an early and accurate diagnosis is very important. If you suspect your baby may be allergic to cows’ milk protein, you should always discuss this with your doctor or healthcare professional.


Digestive CMPA Symptoms

Prevalence of digestive symptoms

Up to 60% of affected infants have digestive symptoms.


Respiratory CMPA Symptoms

Prevalence of respiratory symptoms

Up to 30% of affected infants have respiratory symptoms.


CMPA Symptoms


General CMPA Symptoms

Inconsolable crying is very common in infants with CMPA, while anaphylaxis is very rare.

What are the different types of CMPA?

There are two types of cows' milk protein allergy depending on how the immune system reacts. The first type is defined by symptoms that are ‘immediate’. This is when symptoms are caused by the immunoglobulin E antibody (IgE). Typically, these allergic symptoms happen within minutes of consuming cow’s milk or up to two hours afterwards. This is known as IgE-mediated.

The other type of CMPA is ‘delayed’, where symptoms are slow to appear. This is described as non-IgE mediated and is the most common type. The symptoms usually develop from two hours after consumption but can take up to a week to appear.

What to do if you suspect your baby might be allergic to cows’ milk protein

If you’re unsure if your baby has a cow’s milk allergy or not, try answering a few simple questions with our symptom checker. This can help your doctor make an accurate CMPA diagnosis.

Fill out the symptom checker here *

* Just because your baby has some of the symptoms of CMPA it does not mean they have CMPA, especially as a lot of the symptoms of CMPA are similar to the expected behaviour of your baby or they overlap with other common problems. Getting an accurate diagnosis is important. If you suspect you baby maybe allergic to cow’s milk protein, you should always discuss this with your doctor or healthcare professional.

Preparing for your doctor's appointment will help to ensure that they’re aware of all your baby's symptoms.

During your appointment, the doctor may suggest carrying out the following tests to make a cow’s milk allergy diagnosis:

Elimination diet followed by food challenge

During this form of testing, cow’s milk protein is completely eliminated for 2-6 weeks, then reintroduced to see if the symptoms reappear to prevent misdiagnosis and unnecessary dietary exclusions.

Skin prick test

With a skin prick test, the skin is firstly scratched and then a tiny amount of the food/allergen is added to the skin.

Blood test

During a blood test, your physician will take a small amount of blood in order to investigate for antibodies against a protein in cow’s milk known as ‘immunoglobulin E IgE’.

Elimination diet and food challenge

Your doctor or health care professional (HCP) will first examine your baby and ask about any symptoms you may have noticed. If cows' milk allergy (CMPA) is suspected, your doctor may then perform specific allergy tests to confirm the diagnosis. These tests may include a blood test, skin prick test, patch test, or elimination diet followed by a food challenge.

It is important that you do not experiment with a cows' milk-free diet for your baby without recommendation and guidance from your HCP. Based on the age of your baby and the severity of the symptoms, your doctor or HCP will recommend the most suitable solution.

The best way for your doctor or HCP to confirm or exclude the diagnosis of CMA is through an elimination diet, which involves eliminating cows' milk protein from your baby’s diet, followed by a food challenge, in which cows' milk protein is reintroduced. Although CMA is rarely observed in breastfed babies, if you are breastfeeding, your doctor will help you eliminate cows' milk protein from your diet.

If your baby has an allergic reaction to cows’ milk protein, you are likely to notice improvements very quickly after starting the elimination diet; most symptoms will disappear within 2 to 4 weeks, and all should completely disappear within 6 weeks. If improvements in symptoms are seen, then your doctor will suggest reintroducing cows' milk protein into your baby’s diet in small amounts to check if symptoms reappear to confirm the diagnosis. If avoiding cows' milk protein does not help your baby, it is unlikely that your baby has CMA, and your doctor or HCP will investigate other possible causes of the symptoms observed.

If the diagnosis of CMPA is confirmed, the good news is that with the support of your doctor, it can be managed. The key is to seek support from your doctor as early as possible to ensure a fast and accurate diagnosis.

Diagnosis of a cows’ milk protein allergy should not impact your breastfeeding routine. Mothers are encouraged to continue breastfeeding even when their babies have CMA. This usually requires qualified dietary counselling to completely exclude all sources of cows’ milk protein from the mother’s diet.

IMPORTANT NOTICE: Breastfeeding is the best form of nutrition for babies and provides many benefits to babies and mothers. It is important that, in preparation for and during breastfeeding, you eat a healthy, balanced diet. Combined breast and bottle feeding in the first weeks of life may reduce the supply of your own breastmilk, and reversing the decision not to breastfeed is difficult. Always consult your healthcare professional for advice about feeding your baby. The social and financial implications of using infant formula should be considered. Improper use of an infant formula or inappropriate foods or feeding methods may present a health hazard. If you use infant formula, you should follow the manufacturer’s instructions for use carefully – failure to follow the instructions may make your baby ill. Formula for special medical purposes intended for infants must be used under medical supervision.