Allergic reactions to cow's milk
7-minute read
If you think someone is having an allergic reaction, seek medical advice urgently as symptoms can worsen rapidly. If breathing is affected, call triple zero (000).
Key facts
- Allergy to cow’s milk is one of the most common food allergies in childhood — it’s different to lactose intolerance.
- An allergy to cow’s milk can cause mild symptoms, or more a serious reaction such as anaphylaxis.
- A cow’s milk allergy is diagnosed by a doctor.
- Cow’s milk allergy can be managed by avoiding milk products.
- Most children with a cow’s milk allergy will grow out of it by the time they are school age.
What is a cow’s milk allergy?
Allergy to cow's milk is one of the most common food allergies in childhood. It affects about 1 in 50 preschool children.
Most children grow out of it by the age of 3 to 5 years. Less than 1 in 1000 school-age children have cow's milk allergy.
What are the symptoms of cow’s milk allergy?
The symptoms of allergy to cow's milk can be mild to severe.
Mild to moderate symptoms include:
- a rash (eczema or hives)
- swelling of the lips, face and eyes
- tingling mouth
- vomiting and diarrhoea
- gastro-oesophageal reflux (GORD)
Anaphylaxis is the most severe allergic reaction and requires immediate treatment. Symptoms include:
- noisy breathing or wheezing
- swelling of the tongue
- swelling or tightness in the throat
- hoarse voice
- loss of consciousness and floppiness in babies or young children
What causes cow’s milk allergy?
Cow's milk allergy is often due to an immune system reaction against milk proteins.
How is cow’s milk allergy different to lactose intolerance?
Lactose intolerance is when the body has trouble digesting lactose. Lactose is the natural sugar found in milk. It can cause symptoms such as:
- diarrhoea
- vomiting
- stomach pain and gas (wind or bloating)
It’s different to cow's milk allergy, which is when your immune system reacts to the protein in milk. Lactose intolerance does not cause rashes or anaphylaxis.
When should I see a doctor?
The diagnosis of cow's milk allergy is often obvious, as symptoms occur soon after exposure to milk proteins.
Symptoms usually appear within 15 minutes to 2 hours of consuming milk. When symptoms of cow's milk allergy are more delayed, it can be harder to diagnose.
If you experience symptoms of cow’s milk allergy, see a doctor.
How is cow’s milk allergy diagnosed?
Your doctor can confirm a diagnosis of cow’s milk allergy through skin prick allergen tests. Not every child who has a positive allergy test will develop symptoms when exposed to milk.
The Australasian Society of Clinical Immunology and Allergy recommends that cow’s milk allergies are diagnosed in consultation with a specialist.
How is cow’s milk allergy treated?
There are a few ways that the symptoms of cow’s milk allergy can be managed and treated.
Preventing an allergic reaction
If you or your child are allergic to cow’s milk, you need to remove all cow’s milk from your diet. This can be difficult — milk is an ingredient in many foods, such as:
- bread
- cereals
- sausages
- baked goods
- chocolate
- sweets
- salad dressing
It can also be found in some milk, cream and butter substitutes that are labelled ‘non-dairy’.
If you have a cow’s milk allergy, follow your doctor’s instructions and check food labels very carefully. Watch out for other words used to describe milk on food labels, such as:
- butter, ghee and curd
- cream and buttermilk
- dairy
- milk solids
- whey
- yoghurt
- cheese
- casein and caseinates
Some labels warn that the food ‘may contain traces of milk’. This usually means the food is made in a facility that also makes a food containing milk. Talk to your doctor about whether it’s safe for you to eat those foods.
You may also need to avoid milk from other animals, such as:
- goats
- sheep
Most children will also react to these milks if they have cow’s milk allergy.
Managing cow’s milk allergy
If you or your child has a cow’s milk allergy, talk to your doctor. They can help you make a personal allergy action plan to manage your allergic reaction.
You can find out more about allergy action plans on the Australasian Society of Clinical Immunology and Allergy (ASCIA) website.
Your doctor may prescribe an adrenaline autoinjector.
Alternatives to cow’s milk
It’s important to important to find alternative sources of calcium.
For children aged up to 1 year, there are alternatives to cow’s milk, such as:
- Cow’s milk based extensively hydrolysed formula (EHF) is formula that is treated to break down cow’s milk proteins, but it is not suitable for babies who have had anaphylaxis to cow’s milk.
- Soy protein formula is tolerated by most babies and is recommended in babies aged over 6 months.
- Rice protein-based formula may be used as an alternative to soy protein formula or EHF.
- Amino acid-based formula is used when EHF or soy protein formula is not tolerated.
If your child is aged over 1 year, your doctor and/or dietitian may recommend:
- soy milk
- rice milk
- oat or nut milks
Alternative milks enriched with calcium must contain around 120mg/100mL to be a suitable cow’s milk replacement.
Talk to your doctor or a dietitian about cow’s milk alternatives for your child.
Can cow’s milk allergy be prevented?
Unfortunately, cow’s milk allergy cannot be prevented, but it can be managed.
Complications of cow’s milk allergy
A severe allergic reaction to cow’s milk can cause anaphylaxis which:
- can be life threatening
- should always be treated as a medical emergency
Resources and support
This factsheet from The Royal Children’s Hospital lists alternative foods to cow’s milk. Translated fact sheets can also be found on the website.
For more information on anaphylaxis and setting up a personal action plan, visit www.allergy.org.au.
You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.