Milk Allergy in Babies: What You Need to Know

Team Peanut
Team Peanut2 months ago6 min read

Want to know more about a milk allergy in babies? We explain how to spot it, and what to do if your little one’s allergic.

Milk Allergy in Babies

So many things can give babies upset stomachs, runny noses, and rashes.











But what if your baby has a milk allergy?

Could it be milk in your diet or in their formula that’s causing these issues?

How do you spot a milk allergy in babies?

And how do you handle it if your baby has an allergic reaction?

Don’t worry mama, we’ve got your back!

We’re going to take you through everything you need to know to identify and manage a milk allergy in babies.

In this article: 📝

  • How common is a milk allergy in babies?
  • What causes a cow milk allergy in babies?
  • What are the symptoms of a milk allergy?
  • Serious allergic reactions
  • What does a dairy intolerance look like in babies?
  • How do I know if my baby has a milk allergy?
  • How long does it take to know if baby is allergic to milk?
  • What does milk allergy baby poop look like?
  • Milk allergy in babies: the bottom line

How common is a milk allergy in babies?

When we talk about a milk allergy in babies, we really mean an allergy to the proteins in cow’s milk.

Cow’s milk is used in pretty much all standard baby formula.

And it can also find its way into breast milk through the mother’s diet.

An allergy to cow’s milk is actually one of the more common allergies in babies.

It affects up to 5% of 1-year-olds.

It’s more common in babies fed formula than it is in breastfed babies.

But the good news is that children usually grow out of it.

What causes a cow milk allergy in babies?

Milk allergies are caused by your baby’s immune system wrongly identifying milk proteins as a threat.

It then goes on the warpath to remove them from the body as quickly as possible.

To do that, it releases chemicals called “histamines.”

It’s histamines that lead to the range of symptoms that appear when your little one has an allergic reaction.

They’re all part of the plan to get rid of the milk proteins fast.

But they’re no fun for your baby (or for you).

What are the symptoms of a milk allergy?

Common milk allergy symptoms in babies include:

  • A blocked or runny nose, or other symptoms similar to hay fever.
  • Stomach problems like cramps, colic, diarrhea, constipation and sickness.
  • Rashes or skin inflammation, eczema that doesn’t clear up, or swelling around the eyes, lips and face.

Serious allergic reactions

Sometimes symptoms can be serious, and they can come on quickly.

A severe allergic reaction is known as anaphylaxis.

If your baby shows any of the following symptoms, take action right away:

  • Swelling in the mouth or throat
  • Wheezing, coughing, difficulty breathing or shortness of breath
  • Symptoms involving two different parts of the body — like diarrhea together with a rash

If your baby has an epinephrine auto-injector, use it immediately.

And always dial 911 to seek emergency help, even if it looks like their symptoms are improving.

What does a dairy intolerance look like in babies?

A food intolerance is quite different to an allergy.

It doesn’t have anything to do with your baby’s immune system.

Instead, their digestive system is having problems breaking down a particular substance.

In milk, the culprit will be lactose.

Lactose is a type of sugar, and it’s difficult for some digestive systems to handle.

Some of the symptoms can be quite similar to those of a milk allergy.

Your baby could be irritable or colicky, and have loose stools.

But if there are signs of blood in their poop, it’s more likely to be an intolerance than an allergy that’s to blame.

How do I know if my baby has a milk allergy?

Babies with a milk allergy may display symptoms within a few minutes of having cow’s milk.

But sometimes there can be a delay of hours, or even days, before the symptoms appear.

The two kinds of reactions have different names.

An allergy where the symptoms appear immediately is known as “immediate CMA” or “IgE mediated” CMA.

The CMA stands for “cow’s milk allergy.”

If the symptoms take longer to show up, it’s “delayed” or “non-IgE mediated” CMA.

The types of symptoms can change over time.

And sometimes they can be more serious than others.

Fortunately, doctors can test for a milk allergy in babies.

So if you suspect that your little one is allergic, get them checked out.

The doctor will talk through your baby’s symptoms and ask about any family history of allergies.

They may also take a look at your little one’s poop and do a skin prick test.

It isn’t possible to cure a milk allergy, although most children will outgrow it fairly quickly.

So the way of managing it is simply to remove it from their diet.

How long does it take to know if baby is allergic to milk?

If no longer having cow’s milk results in your baby’s symptoms clearing up, it’s a good bet that they’re allergic.

Sometimes, doctors advise reintroducing milk after about a week to check whether it’s really the cause of the problem.

Skin tests are another way to provide a fast diagnosis.

The doctor will make a tiny scratch on your baby’s skin and place some milk protein there.

Any sign of swelling in that area indicates that they have a milk allergy.

Almost all children with a milk allergy show symptoms before they’re one year old.

But they also tend to outgrow it by the time they’re about 3.

By then, their immune system is better developed, and can recognise that milk proteins aren’t a threat.

What does milk allergy baby poop look like?

Not all babies with a milk allergy will have unusual poop.

But the contents of your little one’s diaper can be a clue that they either have a milk allergy or are intolerant to lactose.

Look out for:

  • Runny or loose poop — diarrhea is a common symptom of a milk allergy.
  • Bloody poop — this can be a sign that your baby’s colon is inflamed, which is often the result of an intolerance to a particular food (like lactose).
  • Green poop or poop with mucus.

Milk allergy in babies: the bottom line

A milk allergy in babies is pretty common.

And while the symptoms can be worrying, the good news is that they’ll clear up when the milk is removed from your little one’s diet.

That might make things more complicated for a while.

But your doctor or dietician will be able to advise on alternatives to milk for you.

This might mean altering your own diet if you’re breastfeeding, finding a different formula if your baby is formula-fed, or seeking out calcium-rich dairy alternatives for toddlers.

So hold tight, mama.

Chances are, in a few years, that milk allergy will be a thing of the past.

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