What is cow's milk protein allergy in children


What is cow’s milk allergy?

Cow’s milk protein allergy (CMPA) is when the body’s immune system reacts to the proteins found in cow’s milk. It is also called cow’s milk allergy. 3 in 100 babies may develop cow's milk allergy in the first year of life. Many foods and drinks contain cow’s milk protein, including normal infant formula. There are two types of cow’s milk allergy:

1. Delayed onset – also called non IgE mediated

This is the most common type. Symptoms come on from 2 hours up to 3 days after having anything with cow’s milk protein in it. There will be more than one symptom that affects the skin and/or digestive system. These include eczema, diarrhoea, constipation, reflux, blood in stools.

Most children with this type of cow’s milk allergy will grow out of it between the age of 1—2 years.

It is important to know that these symptoms can be present when there is not an allergy to cow’s milk. If you have any worries about your baby’s feeding or symptoms, please contact your health visitor or GP.

Your healthcare professional may advise a cow's milk elimination diet for 2-4 weeks if they think your baby has a delayed cow's milk allergy. This is generally followed by a home milk reintroduction challenge to confirm or exclude the allergy. This is the only test available for this type of allergy.

2. Acute/Immediate onset – also called IgE mediated

Your baby will have symptoms within seconds or up to 2 hours after having cow's milk. Symptoms can affect the skin such as red and itchy hives or swelling around the eyes, lips, or face. Sometimes there is immediate vomiting or diarrhoea. In a small number of cases a reaction called anaphylaxis may occur. If you notice symptoms of anaphylaxis, such as swelling of the tongue or breathing difficulties, seek immediate medical help.

If your baby is having immediate symptoms to cow’s milk your GP can refer them to secondary care. Skin prick testing or specific IgE blood tests can help your doctor diagnose the allergy. Your baby will need a cow's milk free diet. You should not attempt to reintroduce cow's milk or foods containing cow's milk to your baby, unless advised by your allergy specialist.

If your child has a cow’s milk allergy, breastfeeding remains the best way to feed them.

Breastfeeding can continue in babies with a cow’s milk allergy. It is rare for babies to react to the cow's milk in mother’s breast milk. If you have any concerns regarding feeding your baby, it is important to seek help from an infant feeding specialist (see below). Your healthcare professional may recommend a breastfeeding mother removes dairy and all foods containing cow's milk from their diet for a trial of up to 6 weeks. Dairy products are an important source of calcium in diets of breastfeeding mothers so a supplement of calcium alongside vitamin D is advised.

Ask your GP or health visitor to refer you to a paediatric dietitian if they have not already. Paediatric dietitians are specialists in how to feed your baby with a cow's milk allergy. They can help with tips on introducing solids, alternative milks and discuss the right time to reintroduce cow's milk.

More information and support

Infant feeding support for Hertfordshire residents: contact health visiting on 0300 123 7572.

Infant feeding support for west Essex residents: contact health visiting on 0300 247 0122 (Switchboard, Essex Child  and Family Wellbeing Service).

You can find more about cow’s milk allergy on Allergy UK’s website, or helpline on 01322 6198.

Accessibility tools