Allergy to cow's milk is an immune system reaction (true allergy) against proteins in milk. About 1 infant in 50 is allergic to cow’s milk and dairy products. Most of these children will outgrow cow’s milk allergy by the time they are 4 years old. Exposure to even a trace amount of milk protein can be a problem for someone with milk protein allergy. True allergy to cow’s milk is rare in adults.
Anaphylaxis is the most severe allergic reaction and requires immediate treatment. 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).
Diagnosis of cow’s milk allergy is often obvious when symptoms occur within minutes of exposure. Skin prick allergen tests from your doctor may also help. When symptoms are delayed, cow’s milk allergy can be harder to diagnose.
Lactose in cow’s milk is a problem for people who lack the enzyme lactose, but this is different to cow’s milk allergy.
Choosing Wisely and allergen testing
The Australasian Society of Clinical Immunology and Allergy recommends you should speak to your doctor or specialist about the benefits and safety of allergen immunotherapy or before attempting any allergy testing or treatment. For further information, visit the Choosing Wisely Australia website.
Follow the links below to find trusted information about allergic reactions to cow's milk.
Last reviewed: October 2016