The basics of CMPA in babies | The Allergy Mums Club

If you think your baby may have CMPA (cow’s milk protein allergy), and you are wondering what to do, I am here to help! This is your practical guide to understanding CMPA in babies. I will point you towards evidence based information, supported by real life experiences of other allergy mums.

It’s important to note that this post is not intended to replace medical advice. The purpose is to arm you with information to be able to advocate for your child (and yourself!) . You should always talk to a healthcare professional about any concerns you have.

Knowledge is power!

If you suspect your baby is reacting to dairy, either via your breastmilk or directly, the first thing you need to do is get informed. In reality, that is easier said than done. Having had two babies with multiple allergies, I’ve been in your position. I know how hard it can be to find accurate information, especially when you are sleep deprived and stressed! Googling at 2am about symptoms, and getting sucked into the archives of facebook groups and chat forums can just add to the confusion.

I’m going to point you to the information I wish I had known when I first suspected my baby may have an allergy. My journey would have been so much easier if I knew the key facts about CMPA in babies and what support I should expect. When I started sharing experiences of other allergy mums, I realised I was far from alone struggling in those first few months.

I’ve pulled out key bits of information from a range of trusted sources in a way I hope will be helpful. At the bottom of this post I have listed sources, for anyone who fancies doing some more in depth reading.

Read on to find out:

What is CMPA?
Types of CMPA in babies
What are the symptoms of CMPA in babies?
What should I do if I suspect my baby has CMPA?
How is CMPA diagnosed and managed in babies in the UK?
Can I continue to breastfeed if my baby has CMPA?
What are the formula options for babies with CMPA?
How to get started with dairy free weaning
Where can I get further support if I suspect my baby has food allergies?
Where can I get more information about CMPA in babies?

What is CMPA?

CMPA stands for Cow’s Milk Protein Allergy. It is also commonly referred to as a dairy allergy or a cow’s milk allergy. It is NOT a lactose intolerance or lactose allergy.

CMPA is one of the most common food allergies among children. The NHS states that “Food allergies happen when the immune system – the body’s defence against infection – mistakenly treats proteins found in food as a threat. As a result, a number of chemicals are released. It’s these chemicals that cause the symptoms of an allergic reaction.”

Types of CMPA in babies; immediate and delayed onset

There are two types of cow’s milk protein allergy, both of which affect the immune system but in different ways.

Immediate onset (IgE) Cow’s Milk Protein Allergy. These are symptoms which typically appear immediately after consuming the allergen, or within two hours. There is generally a clear link between what has been eaten and the subsequent reaction.

Delayed onset (non-IgE) Cow’s Milk Protein Allergy. This is the most common type of dairy allergy. Symptoms can occur from anywhere between 2 and 72 hours after consuming the allergen. Unfortunately the delayed nature of the reaction means that diagnosis can be more challenging. This type of delayed allergy used to be referred to as an intolerance, but this term should no longer be used. It is now clear that it is an allergy affecting the immune system.

Allergies to many different foods can fall into these two categories. If you want to know more, The Allergy Team have further information on their website about IgE and what it is.

What are the symptoms of CMPA in babies?

You are about to read about a long list of symptoms. When you’re finished your head may be spinning! The list of potential symptoms of dairy and other food allergies in babies is long, and some require you to know what ‘normal’ is – but I certainly didn’t know what normal was when I was a new mum!

What is so important here is to remind you to trust your gut. You may not know the answer, but if you feel that something is bothering your baby then it is worth pursuing. I hear this time and time when asking other allergy mums to share their experiences and top tips. Many times, you will see that one of the top tips is to trust your instinct. On reflection, they wish they had trusted theirs sooner.

Symptoms of CMPA (and other food allergies) may develop within the first weeks or months of a baby’s life, and can affect both formula fed and breastfed babies. In some cases symptoms will only become apparent when weaning starts.

The timing and type of symptoms will differ depending whether your child has an immediate (IgE) or delayed (non-IgE) dairy allergy. Although timing after exposure will differ, both often affect the skin, and/or the digestive system. Both can result in some behavioural symptoms such as excessive crying. Some babies may have only one or two symptoms which are very persistent and/or severe, whereas others may experience many of the symptoms.

Allergy UK has a really helpful comprehensive table of symptoms split out by delayed (non-IgE) and Immediate (IgE) onset. I have listed some common examples below:

Common Non-IgE (delayed onset) symptoms:

Itchy skin and unexplained rashes
Eczema, particularly that which doesn’t improve with initial treatment, or returns straight after further treatment (e,g steroid use)
Gastric discomfort and trapped wind
Frequent, very loose stools (diarrhea) OR very hard stools.
Poo which contains mucus or blood
Reflux – either resulting in vomiting, or silent reflux
Weight loss or failure to gain weight
Excessive crying

Common IgE (immediate onset) symptoms

Sudden flare of eczema, hives, or itchy rash
Swelling of eyes or face
Vomiting or diarrhea during or soon after feeds
Runny or itchy nose and eyes
Coughing, wheezing, difficulty in breathing during or soon after feeding

Any reaction which causes any swelling around the head or neck, problems with breathing or loss of consciousness/floppiness require immediate medical attention – it could be a sign of anaphylaxis. It is important that you familiarise yourself with the symptoms of anaphylaxis and what to do if you suspect it by looking at the resources on the Allergy UK anaphylaxis page. Anaphylaxis is a serious medical emergency. If you are in any doubt, call for an ambulance straight away and state anaphylaxis. Those with an Adrenaline Auto-Injector (AAI), should administer it without delay.

If your child has been given an AAI, you may find this Parent’s Guide to Adrenaline Auto Injectors useful reading.

Could my baby have a dairy allergy?

Was I right that your head is now spinning? Some of the symptoms (difficulties breathing, blood in poo) clearly need immediate medical assessment. But many of the more common non-IgE symptoms (such as reflux and diarrhea) are things which most babies experience from time to time. This can make diagnosis additionally challenging. The Milk Allergy in Primary Care (MAP) guideline states that if these symptoms are persistent and continue despite first line treatment then an allergy should be considered, particularly if there are multiple or severe symptoms. Allergy UK state delayed onset CMPA should be considered if symptoms are accompanied by restless sleep or excessive crying.

I would suggest having a browse through some Allergy Mums Club Stories to learn from others who have been in your position. You will start to see that there is a big range of possible symptom combinations. You may find a story which is very similar to your own situation.

What should I do if I suspect my baby has CMPA?

Make an appointment to talk to your GP or family doctor as soon as possible. Before your appointment I would recommend spending some time educating yourself about CMPA and food allergies in babies. Which you are doing by reading this post! Informing yourself can help you give the doctor all the information they need to make a diagnosis.

You should also start logging symptoms as soon as you can. Make a note of what your baby (or you, if breastfeeding) has eaten. Take photos and videos of things like reflux and discomfort when feeding. This can really help when you talk to the medical professionals. It assists them to distinguish symptoms suggestive of an allergy from the ‘normal’ range of what all babies experience occasionally. You can do this using a symptom tracker, but personally I found that just using the notes on my phone, and a folder to save photos and videos was less overwhelming than doing something structured.

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How is CMPA diagnosed and managed in the UK?

The diagnosis of food allergies, especially in babies, is not straightforward. Because of this, it is not uncommon for parents to experience delays in a diagnosis being made for their children. A report from the All Party Parliamentary Group for Allergy and the National Allergy Strategy Group in October 2021 reported that it takes an average of five GP visits before cow’s milk allergy is diagnosed in infants.

There are professional guidelines which can guide doctors to a faster diagnosis. In reality, GPs have to have such a broad range of knowledge, it can mean they are not aware of all guidelines. But once you know about them you can share them! This can really help you navigate the system and ensure that the support you are being given is appropriate. The relevant guidelines are:

Milk allergy in primary care guideline; the iMAP milk ladder for the reintroduction of diary accompanies this guideline. You can read more about this in my basics of the iMAP milk ladder post.
NICE guideline – Cow’s Milk Allergy in Children
NICE guideline – Food allergies in under 19s

Can I continue to breastfeed if my baby has CMPA?

Yes, you absolutely can! In fact, the milk allergy in primary care guideline was updated in 2019 with one of the express aims of ensuring that mothers were encouraged and supported to keep breastfeeding. Guidance to GPs which introduces the guideline states “Breastfeeding mothers of infants with CMA [Cow’ Milk Allergy] should be referred alongside their infant to a paediatric dietitian for advice about their own diet. Please do not advise a mother to stop breastfeeding on the basis of a diagnosis of CMA. Your encouragement can help her to continue for as long as she wishes to.”

If you have been exclusively breastfeeding and your child has been showing symptoms of a dairy allergy then you should completely exclude dairy, in all forms, from your diet. Unfortunately this means you will need to check a lot of labels! In the UK, all top 14 allergens have to be emphasised on the ingredients label (usually in bold or underlined). This makes checking a bit easier. If you are struggling for dairy free meal ideas, you may find my 4 week meal plan helpful.

If you do remove dairy from your diet, it is very important that you ensure that you are getting adequate levels of calcium. The BDA calcium fact sheet shows that breastfeeding women need 1250mg of calcium a day, nearly double the standard 700mg needed for most adults. The factsheet has an informative section on non-dairy sources of calcium to include in your diet.

You may be advised that you can keep dairy within your own diet if your baby showed no symptoms when exclusively breastfed. Not all babies will react via breastmilk.

What are the formula options for babies with Cow’s Milk Protein Allergy?

There are two main options for dairy free ‘hypoallergenic’ formulas:

Extensively hydrolysed formulas – These formulas do contain milk proteins, but they have been extensively broken down making them much less likely to cause an allergic reaction. This type of formula is likely to be prescribed as a first line option for babies showing mild to moderate symptoms.

Amino acid formulas – These formulas are based on the individual building blocks (amino acids) that make up a protein, and contain no dairy at all. Amino acid formulas will generally be recommended for babies showing more severe symptoms, or those who have not been able to tolerate extensively hydrolysed formula.

You will need to discuss with your doctor or allergy specialist which is the best milk to start with. They are extremely expensive to buy, and you will need a prescription.

There are a number of different options within each category of formula, and you may need to try a couple of different brands to find which one suits your baby best. Don’t be afraid to ask to try a different formula, particularly if you have started on an extensively hydrolysed formula and you are still seeing symptoms.

Make sure you log symptoms and take pictures/videos to help your doctor understand why you think a different option is needed.

The BDA Association of UK Dietitians has a good fact sheet about suitable alternative milks for children with cow’s milk allergy.

How to get started with dairy free weaning

For many parents, weaning is an exciting new chapter in their child’s development. But it can also be a time of uncertainty and anxiety – many of us don’t know what we are doing when it comes to getting our babies started on solids! Either way, finding out that your child has CMPA is likely to change your experience dramatically.

Weaning with a dairy allergy can still be a fun and enjoyable experience, you just need the right information, support and preparation. Check out my Beginner’s Guide to Dairy Free Weaning for lots of information and tips to help you get started. You may also find the following articles helpful when looking for dairy alternatives:

Dairy and soya free yogurts for babies and toddlers
Dairy free cheese for babies and toddlers

Where can I get further support if I suspect my baby has food allergies?

Having a new baby can be exhausting and lonely at the best of times. But if you suspect your baby has CMPA or other food allergies, then chances are you are dealing with a very unsettled baby. And it’s unlikely you are getting any good quality sleep! Even if you have sympathetic friends and family, it can be hard for them to appreciate how difficult symptoms such as reflux and eczema can be when they are not dealing with it 24/7.

Luckily there are places where you can get support, both from professionals and from other allergy parents who truly understand what you are going through. This can make a world of difference. I’ve done a separate post about some great sources of support when you have a baby with food allergies. There is a lot available and it is so important.

Where can I get more information about CMPA in babies?

There is a wealth of information out there about food allergies in babies and children. But it’s not always easy to find, and not all of it is helpful or evidence based… I’ve pulled together a list of informative, verified sources for you to check out if you want to do any further reading:

And remember… you are not alone! Come and join The Allergy Mums Club community on Instagram. And please do get in touch if there are any topics about life as an allergy parent you would like to see covered on this website.

Amy x

Article last updated and sources checked June 2022

The basics of CMPA (cow’s milk protein allergy) in babies