Cow’s Milk Protein Allergy, the basics

This is part one of a four part overview of how to not just survive but thrive with Cow’s Milk Protein Allergy. Here’s what’s coming up:

  1. Cow’s Milk Protein Allergy, the basics
  2. Management of Cow’s Milk Protein Allergy
  3. Cow’s Milk Protein Allergy and Complementary Feeding
  4. Cow’s Milk Protein Allergy, the next steps…


Cow’s milk protein allergy is pretty common in the UK. The proteins which cause the allergic response are casein and whey. The estimated prevalence is between 2-3% of the population. It is common in infants and young children and effects 2-7.5% of infants below the age of 1 year. It is unusual to develop a cow’s milk protein allergy later in life.

Symptoms often include:

  • Diarrhoea
  • Constipation
  • Nappy rash (secondary to diarrhoea)
  • Mucus in stools
  • Blood in the stool
  • Reflux or vomiting
  • Wind, bloating or abdominal pain
  • Swelling of face, lips or eyes
  • Skin rashes (redness or hives)
  • Eczema
  • Runny nose

In rare cases cow’s milk allergy can cause breathing difficulties and anaphylaxis. If at any point your child is unable to breathe, call the emergency services immediately.

Allergies are split into 2 types: IgE mediated and Non IgE mediated (often called intolerances)

IgE mediated allergies can be diagnosed by a blood test or a skin prick test. When the milk protein’s whey or casein are ingested, IgE antibodies are released to fight off the offending proteins which the body sees as a threat. The symptoms often come on very quickly with an IgE reaction and in severe cases can include anaphylaxis.

Non IgE mediated allergies are still true allergies, they tend to have the same symptoms but they are more delayed and would not include anaphylaxis. They are also caused by the immune system but not a specific antibody reaction. There are no diagnostic tests for non-IgE mediated allergies, to diagnose there needs to be a period of elimination and then reintroduction to prove that the symptoms come back. To be honest, not many parents that I have come across reintroduce allergens on purpose once the symptoms are gone.

Cow’s milk allergy can occur both in breast and formula fed infants and there is often a family history of some kind of allergy such as hay fever, asthma or eczema if not cow’s milk-allergy itself. Children do tend to grow out of this allergy with the majority doing so before the age of 5.

Lactose Intolerance

A lot of people confuse cow’s milk protein allergy with lactose intolerance. Which is not surprising considering the similarity of the symptoms and that they both are a reaction to cow’s milk. In lactose intolerance it is the milk sugars that cause the problem, not the protein. With lactose intolerance the sufferer is lacking in the enzyme lactase and is therefore unable to break down the sugar lactose. This means that lactose carries on through the digestive tract causing trouble. Undigested sugars cause symptoms such as: bloating, wind, diarrhoea, constipation and abdominal pain.

Lactose intolerance is often temporary following a gastrointestinal infection. However, there are people who are born unable to digest lactose and they will need a low lactose diet for life. A low lactose diet is not too difficult and is catered well by supermarkets.

Lactose free dairy products are not suitable cow’s milk protein allergy sufferers as they still contain milk proteins.

This printable infographic summarises the differences between cow’s milk protein allergy and lactose intolerance: Cow’s Milk Protein Vs Lactose Intolerance

What do you do if you think your child has a cow’s milk protein allergy or Lactose Intolerance?

The first port of call should be your GP or Health Visitor or you can speak to a Registered Dietitian. Uncomplicated cow’s milk protein allergy can be managed by your GP and it is best practice to be referred to a Dietitian. They will refer you to a Paediatrician or allergy centre if needed. This tends to be if a child has multiple allergies, eczema or asthma.

How to treat Cow’s Milk Protein Allergy

Following a cow’s milk protein or dairy free diet is the only way to treat cow’s milk protein allergy.

Breastfeeding mums may need to eliminate cow’s milk protein from their diets if the infant has symptoms with her milk alone.

Formula fed babies will need to be switched to a specialised hypoallergenic formula. This would need to be discussed wth your GP, Dietitian or Paediatrician. There are soya formulas on the market but these are not recommended in babies under 6 months of age. It is better to speak to your GP, Dietitian or Paediatrician initially.

My next blog post in this series will look in depth at the cow’s milk free diet and management.

If you’d like to speak to me about whether your child has a cow’s milk protein allergy or lactose intolerance contact me via the form below for a free 15 minute conversation. Or telephone directly on 07754 968510.



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