Managing cow’s milk protein allergy in children

Cow’s milk protein allergy (CMPA) is one of the most common issues we see in paediatric allergy clinics. Recent studies suggest that around 1% of children have an allergy to cow’s milk protein. Interestingly, this is split almost equally, with 50% IgE-mediated and 50% non-IgE-mediated. which presents unique challenges for diagnosis and management.

Two Types of CMPA: What’s the Difference?

CMPA is usually grouped into two types, depending on how the immune system reacts.

IgE-mediated CMPA (Immediate reactions)

These reactions happen quickly, often within minutes of having milk. Symptoms may include:

Redness or flushing of the skin
Swelling of the lips, eyes, or face
Hives (raised itchy rash)
Vomiting
In rare cases, a severe reaction called anaphylaxis

These reactions are usually easier to spot because they happen straight after milk is consumed.

Young boy in a teal plaid shirt frowns and gives a thumbs-down to a glass of milk on a table, expressing dislike or disapproval indoors.

A young girl with light brown hair has a concerned expression as she points at a glass of milk in front of her, holding her other hand to her stomach.

Non-IgE-mediated CMPA (Delayed reactions)

This type is more subtle and can be harder to recognise. Symptoms usually appear 2 to 24 hours later, or even longer. Common signs include:

Reflux: Especially reflux that doesn’t improve with usual treatments, or where babies arch their back and cry in pain
Eczema: Particularly eczema that starts early in life and doesn’t improve despite good skincare and steroid creams. In breastfed babies, eczema may flare when mum eats dairy.
Constipation: This is often different from typical constipation. Babies may strain and seem uncomfortable, but still pass soft, normal stools.
Blood in the stool: This can happen, especially in breastfed babies, and is a common sign of milk protein irritation in the gut.

What parents need to know

Babies and cow’s milk allergies

Management strategies: Breastfeeding and formula

It is a misconception that breastfed babies cannot have CMPA; small amounts of protein do pass through breast milk. If a mother excludes dairy to manage her child’s symptoms, she must be supplemented with calcium and Vitamin D to meet both her and the infant’s needs. Always consult your doctor.

For formula-fed babies, clinicians typically choose between two types:

Extensively Hydrolyzed Formula (EHF): The first choice for most because it is cost-effective and may help the child grow out of the allergy faster by exposing them to small, “chopped up” protein fragments.

Amino Acid Formula (AAF): Reserved for severe cases, such as children with growth issues, multiple food allergies, severe eczema, or babies who react to breast milk.

The path to pesolution: The milk ladder

Most children will eventually outgrow CMPA. At 12 months of age, clinicians often recommend starting a “Milk Ladder” to reintroduce dairy. This process begins with baked milk products (such as biscuits), as baking alters the protein structure, making it easier to tolerate.

While the iMAP guideline provides a faster ladder for non-IgE cases, the BSACI guideline offers a slower approach for IgE-mediated allergies to minimise the risk of severe reactions.

The difference between cow's milk protein allergy and lactose intolerance

What is lactose intolerance?

Lactose intolerance is caused by a reduction in an enzyme in the gut called lactase. Lactase is needed to digest lactose, the natural sugar found in cow’s milk. When lactose isn’t broken down properly, it can lead to symptoms such as bloating and diarrhoea. Lactose intolerance is usually temporary in children and often follows a tummy bug. The inflammation in the bowel can take around eight to twelve weeks to settle. During this time, lactose-free milk can be used, and once symptoms have resolved, normal cow’s milk can usually be reintroduced into the diet.

What is a cow’s milk allergy?

Cow’s milk protein allergy, on the other hand, is an immune reaction to the protein in cow’s milk. Because it involves the immune system, the symptoms are very different. Reactions can be mild, such as swelling of the lips or eyes, or hives, but they can also be severe and include anaphylaxis. In this situation, cow’s milk should not be reintroduced unless an allergist or specialist has confirmed it is safe to do so.

Because these are two distinct conditions, it’s important not to confuse them. Lactose-free milk still contains cow’s milk protein, which means it is not suitable for children with a cow’s milk protein allergy, even though it may be appropriate for those with lactose intolerance.

When should I seek help for my child’s cow’s milk allergy?

If your child has immediate reactions to milk, such as swelling, hives, or vomiting soon after feeding, national guidance recommends referral to a specialist allergy clinic. This helps confirm the diagnosis, often using simple tests like a skin prick test, and ensures you receive the right dietary support.

Children with delayed symptoms can often be safely managed by your GP using established guidelines, with specialist input if needed.

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