Select Page
**This post may contain Affiliate links, you can read the full disclosure here for more info**

Our Story

My first baby was suspected to have Cow’s Milk Protein Allergy (CMPA) after he developed a rash at 5 weeks of age. He also had reflux, change in his stools (poo) with lots mucus, and poor weight gain.

I was breastfeeding at the time and occasionally giving infant formula so I stopped the formula and started exclusively breastfeeding. I eliminated all dairy and soya from my diet, resulting in improvement in his symptoms.

It wasn’t easy becoming dairy and soya-free, especially when eating out.


He was referred to an Allergy clinic and started weaning onto solids at 5.5 months of age. We re-introduced soya first into his diet followed by dairy at around 9 months.

My second baby was exclusively breastfed from birth. He developed reflux symptoms and change in stools but was gaining weight ok. I decided to remove dairy from my diet, but as he was otherwise doing well, I chose not to exclude soya at that point.

His symptoms improved and at around 3 months of age, I re-introduced dairy into my diet. He remained well and I wondered if he even had CMPA to begin with. I started weaning him onto vegetable purees at around 5 months.

At around 6 months, I gave him a baby cereal that contained dairy and he started vomiting. After a week or so, I tried to give him my own homemade cereal with a little formula added and he started vomiting again. He had now also developed an eczematous rash which resolved on removing dairy again from his diet. I attempted re-introduction and the eczema recurred.

After resuming a dairy-free diet, he had no further symptoms and some dairy was later successfully re-introduced at 10 months of age. It would seem that he had simply started to tolerate the small amounts of dairy in my breast milk when he appeared symptom-free at 3 months of age.

My third baby was born smaller than expected but her height and weight were on similar centiles on the growth chart. She developed similar symptoms to my first baby minus the rash. She also had poor weight gain but refused any top-ups of expressed breast milk. I eliminated dairy and soya from my diet which resulted in improvement of her symptoms, but not complete resolution. Her weight gain was better, and she started to grow along the 0.4th centile.

She had her routine 8-week vaccinations and started having diarrhoea with a small amount of blood. My boys only had mild diarrhoea lasting a few days after the rotavirus vaccine. In her case, it continued for 8 weeks. The blood was initially thought to be CMPA related, but the Allergist thought it may have been vaccine-related.

Her weight gain started to slow down to the extent that she was now below the 0.4th centile on the growth chart. I had started to cut out various things from my diet wondering if anything was contributing, which all needed to be re-introduced. Despite all this, she was a really happy baby who was meeting all her developmental milestones.

The “delayed” non-IgE mediated type of CMPA that all my babies had can be difficult to diagnose, even for medical professionals. In her case, some of her reflux was probably physiological, and some of her symptoms CMPA-related. Several attempts were made to re-introduce dairy unsuccessfully before 8 months of age. I continued to breastfeed during this time and I had already made the decision to wean her onto solids at 17 weeks of age.  She was able to have some dairy in her diet from around 9 months of age with a slow introduction and now is completely fine with dairy.

What is Cow’s Milk Protein Allergy?

Cow’s Milk Protein Allergy (CMPA) is when the immune system responds abnormally to the presence of cow’s milk protein and thinks that it is a threat. It becomes sensitised so that whenever it is encountered, it mounts a defence against it, producing the symptoms of allergy.

CMPA may be called IgE-mediated or non-IgE mediated, depending on whether it is the result of developing a specific antibody called IgE.

Antibodies are special proteins which your immune system makes to recognise and respond to foreign substances (antigens) so that your body can remove them.


In non-IgE mediated CMPA, other cells are involved. Mixed IgE and non-IgE allergy results from a mix of responses.

The symptoms of IgE-mediated CMPA are immediate (usually within 30 minutes, up to a couple of hours), whereas non-IgE mediated CMPA is usually delayed (usually between 2 hours and a few days).

CMPA can affect both formula-fed and breastfed babies, although it tends to be less common in babies that are breastfed.

Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.

Are cow’s milk protein allergy, cow’s milk protein intolerance, and lactose intolerance the same thing?

People often get confused between these terms but they are different conditions with different underlying mechanisms causing the symptoms. The management is also different, so it is important to understand the differences.

CMPA is the result of the immune system’s response to cow’s milk protein and is described above.

Food intolerance symptoms can cause a range of symptoms such as non-specific gut symptoms, headaches, and tiredness. There tends to be a delay between eating the food and developing symptoms.


Food intolerances aren’t immune-mediated but we don’t know the exact cause. Sometimes, non-IgE mediated CMPA is mistakenly referred to as cow’s milk protein intolerance.

Lactose intolerance is when your body doesn’t have enough lactase which is needed to digest the sugar lactose which is the main sugar in milk. The lactose then stays in the gut, leading to the symptoms of lactose intolerance.

Lactose intolerance symptoms can begin within a few hours and include excessive flatulence, abdominal pain, and diarrhoea. It is not common in babies. When it does occur in infancy, it is usually following a gastrointestinal illness, and temporary, lasting a few weeks. Lactose-free products are available. These are not suitable for babies with CMPA as they still contain cow’s milk protein.

Symptoms of Cow’s Milk Protein Allergy

Symptoms may be immediately after consuming cow’s milk protein, or delayed, occurring some time later. The following list is not exhaustive:


IgE mediated

  • Skin changes, e.g. rash/redness, itching, hives (raised itchy bumps), flare of eczema
  • Swelling, e.g. lips, tongue, face, around eyes
  • Gastrointestinal, e.g. nausea, abdominal pains, diarrhoea, vomiting
  • Breathing difficulties, e.g. chest tightness, cough, shortness of breath
  • Hayfever-like symptoms, e.g. sneezing, runny nose, congestion
  • Severe casesanaphylaxis – affecting the whole body and potentially life-threatening.

Non-IgE mediated

  • Skin changes, e.g. rash,/redness, bottom redness, itching, eczema 
  • Gastrointestinal, e.g. reflux, vomiting, diarrhoea, constipation, blood or mucus in stools, refusal to feed
  • Slow weight gain

Diagnosis of cow’s milk protein allergy

If an IgE-mediated CMPA is suspected, a referral will be made to an allergy clinic and further tests may be carried out such as skin prick testing or a blood test.

Unfortunately, there currently aren’t any reliable tests to confirm the diagnosis of a non-IgE mediated CMPA. Diagnosis is made on symptoms and any signs present as well as response to dairy elimination and re-introduction back into the diet. We usually advise dairy elimination for 2-6 weeks before reaching a conclusion on whether it has made any difference to the symptoms. Keeping a food and symptoms diary would be helpful in aiding the doctor reaching a diagnosis.



Breastfeeding and cow’s milk protein allergy


Some babies with CMPA are able to tolerate the small amounts of cow’s milk protein in breast milk but will react to formula and other forms of dairy on weaning. Other breastfed babies may react to even small amounts of cow’s milk protein in breast milk which means you would need to follow a dairy-free diet.

There is a myth that I have come across not too infrequently that you need to consume cow’s milk to produce breast milk. Please be reassured that you don’t need cow’s milk in your diet in order to produce breast milk.

You would need to ensure you maintain a calcium-rich diet. Some dairy alternatives are supplemented with calcium and vitamin D but others are not. Breastfeeding mothers on a dairy-free diet are usually advised to supplement with calcium and vitamin D.

Management of Cow’s Milk Protein Allergy


A dairy-free diet needs to be followed and, in some cases, soya exclusion may also be recommended. This is because some babies with CMPA may also react to soya as the protein shapes are similar (more common in cases of non-IgE mediated CMPA).

If baby has symptoms and mum is breastfeeding, they will be advised to follow a dairy-free diet.

If baby is formula fed, a hypoallergenic infant formula milk suitable for babies with CMPA will need to be prescribed. The choice of milk depends on the nature and severity of the symptoms.

Extensively Hydrolysed Formulas (EHF) are whey or casein based. The proteins in these formulas are broken down so that they are less likely to cause an allergic reaction.

Amino Acid Formulas are based on amino acids (think of these as the building blocks of a protein). These are prescribed in cases with severe symptoms, ongoing symptoms on an EHF, or for babies who have symptoms of CMPA whilst mum is breastfeeding.


Other dairy milk alternatives are not recommended as a main drink because they don’t provide the same nutritional value as breast milk or formula.

Babies with CMPA may also react to other mammalian milks (e.g. goat’s milk) as the proteins are similar.

Some babies with CMPA will also react to soya milk. Soya milk also naturally contains phytooestrogens which are similar to the female hormone oestrogen. Due to concerns about potential impact on baby’s reproductive development, it is only recommended in specific situations under medical supervision after the age of 6 months.

Rice milk is not recommended under the age of 5 due to it’s natural arsenic content.

Referral to a paediatric dietician will help continue to monitor growth, nutrition, and support the weaning process and later re-introduction of dairy if appropriate


For mild to moderate, non-IgE mediated CMPA, dairy is usually re-introduced using a “Milk Ladder” which has foods that are considered to be least likely to cause an allergic reaction at the bottom of the ladder, and foods that are more likely to cause an allergic reaction further up the ladder. The idea is that you start at the bottom and once that rung is tolerated, you progress up the ladder. 

It is based on the concept that modifying dairy by heating it makes it more tolerable, so you will find more processed and heated foods at the bottom, and fresh milk at the top of the ladder.

This is not suitable for IgE-mediated allergy.


Most children with CMPA, particularly non-IgE mediated CMPA, will outgrow their allergy in early childhood.

Parents often worry that their next child will also have CMPA. Family history of atopy (e.g. allergies, hayfever, eczema, allergy, asthma) is a known risk factor for allergies but it’s not absolute and does not mean that the next child will have an allergy.


 I’d love to hear your thoughts and if you found this post useful, please share!




Amal is a paediatrician and mum/step-mum to four wonderful children. She started MedicMum101 to share tips and experiences on all things motherhood. She enjoys writing about parenting, health, and wellness, as well as other life musings from time to time. When she is not working, writing, or running after the kids, you can often find her working on a new piece of art.

error: Content is protected !!