Cow’s Milk Allergy in Babies: 4 Common Myths (and What You Really Need to Know)

Cow’s Milk Protein Allergy (CMPA) is one of the most common food allergies in infancy. But even though it’s common, it’s still widely misunderstood—by healthcare professionals, online advice, and well-meaning friends and family.

As a paediatric dietitian, I meet so many parents who feel lost in the CMPA maze. They’ve been told their baby’s symptoms are “normal,” that eczema isn’t linked to food, or that everything must be fine because their baby is growing. These myths can delay diagnosis, cause unnecessary worry, or lead to overly restrictive diets.

Let’s break down four of the most common CMPA myths—and replace them with facts that can help you feel more confident and informed.

Myth 1: Eczema has nothing to do with CMPA

Many parents are told that eczema is just a skin issue and has nothing to do with what your baby eats. But in babies—especially under 6 months—eczema can sometimes be an early sign of an underlying food allergy like CMPA.

In my clinic, I often see babies with moderate to severe eczema who haven’t responded to creams or steroids. Parents are frustrated, tired, and desperate for answers. In these cases, CMPA might be playing a role—especially if the baby also has other symptoms like reflux, tummy trouble, or poor sleep.

What I look for:

• Eczema that starts before 3 months

• Little to no improvement with steroid creams or moisturisers

• Tummy issues (like mucus or blood in the nappy)

• Faltering growth

• Family history of allergy

In breastfed babies, we might try removing dairy from the mum’s diet for 2–4 weeks with dietitian support. For formula-fed babies, we often use a special hypoallergenic formula (either extensively hydrolysed or amino acid-based) for 6–8 weeks to see if things improve.

The key takeaway? Eczema can be part of the bigger CMPA picture—especially when other symptoms are present.

Myth 2: Babies with CMPA need to avoid lactose

This one causes a lot of confusion. CMPA and lactose intolerance are not the same thing.

CMPA is an immune reaction to the proteins in cow’s milk (casein and whey). Lactose intolerance is when your baby can’t digest lactose, the natural sugar in milk. Lactose intolerance is very rare in babies under one—especially if they were born at term and are otherwise healthy.

In fact, breastmilk is full of lactose! It helps with calcium absorption and supports the growth of good gut bacteria.

Unless your baby has gut damage (which can happen with severe CMPA or a tummy bug), there’s usually no reason to cut out lactose. And in some cases, using lactose-containing formulas can actually help with taste and feeding.

Myth 3: If your baby is growing well, it’s not CMPA

This one is really important: Just because your baby is gaining weight doesn’t mean they aren’t reacting to milk.

CMPA—especially the non-IgE type—often shows up in babies who are growing fine on the growth charts but still struggle with symptoms like:

• Reflux-like behaviour

• Mucus or blood in stools

• Chronic nasal congestion

• Eczema

• Excessive crying

• Frequent night waking

It’s not just about weight. A baby can grow and still feel uncomfortable, unsettled, or in pain. I always tell parents: symptom resolution is just as important as tracking weight. If your baby’s symptoms persist, they deserve a proper assessment—even if the scales say everything is “fine.”

Myth 4: You have to stop breastfeeding if your baby has CMPA

Sadly, I still hear from mums who’ve been told to stop breastfeeding when CMPA is suspected—or who’ve gone on very restrictive diets without proper support.

Here’s the truth: You can absolutely continue breastfeeding a baby with CMPA. The key is removing cow’s milk protein from your own diet in a way that’s nutritionally safe for both of you.

With the right support, breastfeeding through CMPA is possible—and incredibly beneficial. I often help mums with:

• A clear and realistic elimination plan

• Guidance on getting enough calcium, iodine, vitamin D, and B12

• Support around introducing solids later on

Unnecessary formula changes or stopping breastfeeding too soon can leave mums feeling anxious, confused, and defeated. But with the right help, it doesn't have to be that way.

The Bottom Line

Cow’s Milk Protein Allergy can be tricky to spot, and there’s a lot of misinformation out there. These myths—while common—can delay diagnosis, increase anxiety, and make feeding harder than it needs to be.

The good news? With the right support and clear guidance, CMPA can be managed safely and calmly. No guesswork. No unnecessary food restriction. Just evidence-based advice and a plan that works for your family.

If you suspect your baby has CMPA—or you feel like no one is listening to your concerns—trust your instincts and reach out. Help is available.