Cow’s Milk Allergy In Babies and Children
Cow’s milk allergy (CMP) (also known as cow’s milk protein allergy (CMPA)) is one of the most common food allergies in young children, particularly babies.
It’s estimated to affect 2-5% of children in Australia and New Zealand, but most outgrow their cow’s milk allergy by the age of 1-5.
What causes cow’s milk protein allergy in children?
Cow’s milk allergy occurs when an infant’s immune system reacts abnormally to the proteins in cow’s milk. These proteins may come from the mother’s breast milk (after she has consumed cow’s milk or cow’s milk-containing products) or from cow’s milk protein-containing formulas or foods.
Food allergies happen when the immune system mistakenly treats proteins in foods as a threat. As a result, chemicals are released which then cause the symptoms of an allergic reaction.
We still don’t know why some people develop allergies to food, however, they do appear to be associated with increased gut permeability and gut dysbiosis. Often children who develop food allergies also have other allergic conditions such as asthma, hay fever and eczema.
What are the symptoms of cow’s milk allergy?
Cow’s milk protein allergy can cause a wide range of symptoms, including:
Skin: itchy rashes, eczema, hives, swelling of the lips and face
Gastrointestinal: irritability (colic), abdominal pain, vomiting, wind, diarrhoea or constipation
Respiratory: runny nose, conjunctivitis
Occasionally, CMPA can cause anaphylaxis, severe allergic symptoms such as swelling in the mouth and throat, wheezing, coughing, shortness of breath and difficult, noisy breathing.
This is a medical emergency and immediate treatment is needed. Call an ambulance or go to your local hospital emergency department.
What are the two types of cow’s milk protein allergy?
There are two types of immune reactions that can occur, immunoglobulin (Ig)E-mediated and non-IgE mediated. It’s also possible to have both.
Depending on the type of immune reaction, symptoms can appear immediately (IgE) or can be delayed reactions, occurring up to 48 hours after ingestion (non-IgE).
IgE-mediated (immediate CMPA)
Rapid onset (immediate) allergic reactions to cow’s milk protein, otherwise known as IgE mediated, usually occur within 15 minutes of consuming cow’s milk or dairy products.
They typically present as swelling of lips, face, eyes, hives (urticaria) or welts on the skin, abdominal pain, vomiting and diarrhoea.
Severe allergic reactions (anaphylaxis) to cow’s milk protein can also occur and include noisy breathing or wheezing and swelling or tightness in the throat. Young children may become pale and floppy.
Anaphylaxis should always be treated as a medical emergency, requiring immediate treatment with adrenaline (epinephrine) and calling for an ambulance.
Non-IgE mediated (delayed CMPA)
These are delayed (late) reactions that usually occur more than two hours after consuming cow’s milk protein.
Symptoms include eczema or delayed vomiting and diarrhoea.
Lactose intolerance vs cow’s milk allergy
Lactose intolerance results from a reduced ability to digest and absorb lactose, the natural sugar present in milk and some dairy products, due to the lack of the enzyme lactase.
Symptoms of lactose intolerance are typically gastrointestinal symptoms such as diarrhoea, vomiting, stomach rumbling, stomach cramps and gas.
Lactose intolerance is rare in children under the age of 5, including children with cow’s milk protein allergy. However, transient lactose intolerance can sometimes occur after a bout of gastro.
How is cow’s milk allergy diagnosed?
Skin prick tests or blood tests can be used to diagnose IgE-mediated cow’s milk protein allergy. These tests measure allergen-specific antibodies called Immunoglobulin E (IgE) to cow’s milk.
Tests such as IgG, Vega, kinesiology, hair analysis, bioresonance, Bryan’s or Alcat tests are not evidence-based and not recommended for diagnosing cow’s milk protein allergy or any other allergy.
There is no test to accurately diagnose non-IgE allergies. Diagnosis is typically done by excluding cow’s milk protein for 1-4 weeks and assessing whether symptoms improve or resolve. A planned reintroduction is then needed to confirm the diagnosis.
How is cow’s milk allergy treated?
Currently, there is no treatment for food allergy. In the case of CMA, avoiding foods containing cow’s milk is the only way to prevent symptoms.
If your baby or child is diagnosed with CMA, their doctor or an allergy specialist will provide advice on how it should be managed.
Because cow’s milk contains important nutrients for babies and children, it should be replaced with a suitable alternative so that children are not at risk of nutrient deficiencies. A paediatric dietitian can help with this.
Severe allergic reactions (anaphylaxis) to cow’s milk can be life-threatening, and should always be treated as medical emergencies that require immediate treatment with adrenaline (epinephrine).
What foods need to be avoided?
If a cow’s milk allergy is confirmed, complete exclusion of all foods and drinks containing cow’s milk protein is usually required.
This includes:
Cow’s milk (including A2 milk, lactose-free milk)
Buttermilk
Yoghurt
Cheese
Cream
Sour cream
Butter
Condensed milk
Evaporated milk
Cottage cheese, feta cheese, ricotta cheese and any other cow’s milk-based cheeses
Cheese spreads
Custard
Ghee
Goat and sheep milks (and any other mammalian milks)
Ice cream
Cow’s milk-based infant formula (including HA)
Milk solids
Whey
Lactoalbumin and lactoglubulin
And any other foods containing any amount of cow’s milk protein
Children with cow’s milk protein allergy will in most cases also be allergic to other mammalian milks such as goat’s milk and sheep’s milk. Therefore, complete exclusion of these milks and any foods containing them may also be required.
Cow’s milk is also used as an ingredient in many foods. Foods that may contain cow’s milk protein include the following:
Bread
Baked goods such as cakes, muffins, pastries, slices
Breakfast cereals
Chocolate
Confectionary
Margarine
Soups
Gravy powders
Salad dressings
Pasta sauces
Rusks and
Instant mashed potato
Malted milk and Milo
Snack foods such as crackers
Sorbet and gelati
Processed meat products such as sausages and burgers
Label reading
Because even very small amounts of cow’s milk protein can cause severe allergic reactions in some infants, and because dairy products are a common ingredient, it’s important to check the ingredients list on packaged foods for any ingredients that may contain milk.
Food manufacturers are required by law to list all common food allergens in the ingredients list, including peanuts, tree nuts, seafood, fish, milk, eggs, soy and wheat.
‘May contain traces of milk’ statements
‘May contain traces of milk’ statements are sometimes present on food labels. These statements are used to indicate that the products may have been contaminated with milk during processing or packaging. The statements are voluntary, therefore, a product that doesn’t display the statement may be no safer than one that does.
The risk of an allergic reaction occurring due to contamination during processing is very unlikely. However, for children with severe food allergies, it may be best to contact the manufacturer to find out more about their food safety procedures.
Cow’s milk allergy and breastfeeding
Breastfeeding should be encouraged to continue even when a cow’s milk allergy is suspected or has been confirmed.
However, because cow’s milk protein passes into breastmilk and then through the breastmilk to the infant or child, removal of cow’s milk protein from the mother’s diet may sometimes be necessary, although this is rare and should only be done with the guidance of a healthcare professional.
If you are advised to remove dairy foods from your diet, it’s important to ensure you’re getting adequate calcium and vitamin D. A dietitian can guide you on this.
Cow’s milk and dairy alternatives for babies and children
There are several different types of cow’s milk and dairy-free formula options available for children with cow’s milk allergy.
These include exclusively hydrolysed cow’s milk-based formula, amino acid formula, rice-based formula and soy formula.
It’s important to speak to your doctor or dietitian about the most suitable alternative for your child as this will vary depending on their individual circumstances and needs. Some specialised infant formulas require a prescription from a doctor.
Unsuitable alternatives
Some infants with cow’s milk allergy are also allergic to soy, so soy formulas may not be suitable for some children
Lactose-free milk and formula contain cow’s milk protein and are therefore unsuitable for cow’s milk allergy
Goat and sheep’s milk contain similar proteins to cow’s milk and are not suitable for use in children with cow’s milk allergy
Rice milk, oat milk and nut milk have a low protein and fat content and should only be used with the guidance of a dietitian until after the age of 2. If using these products after the age of 2, choose brands with added calcium.
What is a Hypoallergenic Formula?
There are two main types of hypoallergenic formulas recommended for babies with a cow’s milk protein allergy.
Extensively hydrolysed formulas: these contain small chains of cow’s milk protein, making it easier for the baby to digest and less likely their immune system will react to it.
Amino acid formulas: these are totally milk-free formulas that are based on simple amino acid proteins.
How do I know when my child has outgrown their cow’s milk allergy?
Because most children will outgrow their cow’s milk allergy between the ages of 1 and 5, kids who have been diagnosed with CMA should be reevaluated every 6-12 months to assess whether they have developed tolerance to cow’s milk protein.
This is important to avoid unnecessary dietary restrictions which can impact a child’s growth and nutritional status, while also impacting their quality of life and that of their family.
Over 75% of children will achieve tolerance by 3 years of age and >90% by 6 years of age.
The milk/dairy ladder
The milk ladder is an evidence-based guideline for the reintroduction of milk and dairy products for infants and children with mild to moderate non-IgE cow’s milk allergy.
It involves the gradual re-introduction of milk products in stages, starting with foods that contain only a small amount of well-cooked milk and progressing towards uncooked dairy products and finally, fresh milk.
Heating and processing can change the proteins in foods making them less allergenic, meaning milk in baked products is often better tolerated than fresh milk. About 70% of children with cow’s milk allergy can tolerate milk in a baked product. You should not try this at home if your child has been diagnosed with a cow’s milk allergy as severe reactions can occur. Discuss a plan with your doctor before attempting any reintroduction.
For everything you need to know about introducing solids, grab my Step-by-Step Guide to Starting Solids
More Information
ASCIA (The Australian Society of Clinical Immunology and Allergy)
Looking for more advice on feeding babies?
References
https://www.allergy.org.au/patients/food-allergy/cows-milk-dairy-allergy
https://pubmed.ncbi.nlm.nih.gov/22569527/
https://www.nhs.uk/common-health-questions/childrens-health/what-should-i-do-if-i-think-my-baby-is-allergic-or-intolerant-to-cows-milk/#:~:text=Cows%27%20milk%20allergy%20(CMA),by%20the%20age%20of%205.
https://www.nhs.uk/conditions/food-allergy/causes/
https://www.allergy.org.au/patients/allergy-testing/evidence-based-versus-non-evidence-based-tests-and-treatments