Cow’s milk is one of the most common causes of food allergy in infants, affecting about one in 50 children. Most children eventually outgrow their allergy and although symptoms can persist into adulthood, it is rare. Many infants are allergic to other foods as well, such as eggs and peanuts.
Reactions to cow’s milk can include swelling of the lips, face or eyes, hives or welts, tingling of the mouth or wheezing. In some children, gastrointestinal symptoms can include diarrhoea, reflux/vomiting or poor weight gain. Reactions can also include eczema.
The majority of children with cow’s milk allergy have mild symptoms, but a small percentage experience severe reactions called anaphylaxis. Anaphylaxis is the most severe form of allergic reaction and involves several parts of the body, including either the respiratory system and/or cardiovascular system. If your child, or you, is at risk of anaphylaxis, you will be prescribed an adrenaline autoinjector (e.g. EpiPen or Anapen).
Milk allergy occurs when the immune system reacts to the protein in milk. If your child is diagnosed with a milk allergy, you need to completely eliminate milk, dairy products and any foods with milk-containing ingredients from their diet.
Anyone who is worried that they, or their child, may have a milk allergy should seek their GP’s advice, and see a specialist if necessary. Your GP or specialist will make a diagnosis based on the history of previous reactions. The allergy can be confirmed by skin prick tests and/or blood tests to measure the allergy antibody.
Most children tend to outgrow their milk allergy when they get older; almost half by the time they are eight years old, and about 80 per cent by the time they are 16 years old. It is very important to have a reliable diagnosis by a specialist before reintroducing milk, and to seek the advice of a registered dietitian.
In rare cases, usually in infants and toddlers, allergy to cow’s milk can be associated with allergy to beef and other cow-based products such as gelatine. Although this is uncommon, you should discuss any concerns with your specialist or dietitian.
Some infants may develop symptoms of cow’s milk allergy while breastfeeding, as the cow’s milk proteins can be passed into mother’s breastmilk. It may be necessary to avoid milk in the mother’s diet to help improve symptoms in the infant; this should only be done with appropriate medical and dietetic advice. A calcium supplement for the breastfeeding mother is usually required.
Guidelines for the Fonterra Milk in schools programme
Avoiding cow's milk
Replacements for cow's milk
Milk labelling guide
What is lactose intolerance?
Acknowledgments: We would like to thank Dr Jan Sinclair, Paediatric Immunologist, and Jenny Heyward, Paediatric Dietitian, of Starship Children’s Health for their assistance in writing this information. This fact sheet is also based on information provided by the Australasian Society of Clinical Immunology and Allergy.