Introduction

Dairy products are anything that is made from the milk of animals, including:

  • cows
  • sheep
  • goats
  • buffalo
  • camels.

The most common dairy milk allergy is to cow's milk.

Allergic reactions to dairy can develop in the first year of your child’s life. This is because dairy products can be introduced to a child’s diet early through certain types of infant formula and as they start to eat solid foods. 

Dairy allergy is different to lactose intolerance. Lactose is a sugar that is found in dairy. Sometimes, lactose cannot be digested in the bowel, causing pain and diarrhoea. 

Some children will grow out of their dairy allergy by three to five years old.

Like any other allergy, it is important to talk to your child’s doctor before reintroducing foods that have previously caused an allergic reaction.

 Signs and symptoms

Allergic reactions can be fast and happen within minutes of exposure to dairy.

Reactions can include:

  • hives or welts on the skin
  • redness of the skin
  • vomiting and stomach ache
  • tingling and swelling of the mouth, lips, face, and eyes.

Some children can have a more severe allergic reaction called anaphylaxis.

Signs of anaphylaxis include: 

  • wheezing, difficult, or noisy breathing
  • swelling of the tongue
  • swelling or tightness in the throat
  • a persistent cough
  • difficulty talking or a hoarse voice
  • dizziness
  • becoming pale and floppy in young children
  • collapsing.

If your child has signs of anaphylaxis, you should:

  • follow your child’s ASCIA action plan for anaphylaxis if you have one
  • use an EpiPen® or Anapen®, if there is one available
  • call Triple Zero (000) for an ambulance.

Some children can develop a delayed reaction to dairy that takes hours or days. 

Symptoms of a delayed reaction can include:

Some children may also have blood or mucus in their poo.

See your local doctor as soon as possible if your child is showing signs of an allergic reaction for the first time. Symptoms of mild allergic reactions should fade over time. See your local doctor as soon as possible if symptoms do not get better or you are concerned.

Diagnosis

If you think your child has had an allergic reaction that is not anaphylaxis, write down the following and see your local doctor as soon as possible:

  • time the dairy was eaten or drunk
  • time of reaction
  • type of reaction
  • amount of dairy eaten or drunk
  • how it was prepared - for example, given as a drink, used in baking, or served as yoghurt.

A specialist doctor can diagnose a dairy allergy based on your child’s:

  • medical history
  • signs and symptoms
  • results from allergy tests.

Some children will grow out of their dairy allergy. 

A food challenge can be done to figure out whether your child has grown out of their allergy and whether dairy can be reintroduced to their diet safely. Food challenges are done under the supervision of a doctor in the hospital.

Treatment

Your child's doctor will find the best possible treatment for their allergy based on their individual health needs. In most cases, your child must carefully avoid dairy in their diet. Children at risk of anaphylaxis need: 

  • an ASCIA action plan 
  • an adrenaline injector, also known as an EpiPen® or Anapen®.

Your child will also need to learn how to identify foods that contain dairy as they get older and become more independent with their diet.

 Management

Common sources of dairy

Some foods will visibly contain dairy, for example, milky drinks, ice cream, and cheese. 

Dairy is also commonly used in cooking and baking to add moisture to dry ingredients, so it can be difficult to avoid. 

Some common foods that contain dairy include:

  • baked goods - for example, cake, muffins, and biscuits
  • desserts - for example, custard, ice cream, chocolate, and cream
  • foods that have been cooked or fried in butter or ghee
  • dips and sauces - for example, anything including cheese, sour cream or cooking cream
  • common dairy foods and ingredients like cheese, cottage cheese, buttermilk, butter, yoghurt and condensed or evaporated milk
  • protein products like powder or supplements that contain whey
  • infant formula.

Sweets like chocolate and lollies can also contain dairy, so it is important to check the ingredients list, even if the product is labelled as dairy-free or plant-based.

Dairy can also be called different names on ingredient lists, including:

  • casein and caseinates
  • dairy solids
  • hydrolysates - casein, milk protein, whey
  • low-fat milk 
  • malted milk
  • milk derivative
  • milk protein                        
  • milk solids 
  • non-fat dairy solids
  • non-fat milk solids
  • pro-biotics
  • skim milk
  • skim milk solids
  • whey.

Dairy substitutes

Dairy is a common ingredient in baking, cooking and many snack foods, including chocolate. 

A dairy-free diet can be difficult, but making baked goods and other foods using dairy substitutes is possible. Your local supermarket or specialty store may stock dairy substitutes that are made commercially and are labelled for plant-based or vegan diets. 

These products are often made of soy, coconut, oats, rice, or tree nuts and can include replacements for: 

  • yoghurt
  • milk
  • ice-cream
  • cream
  • cheese.

 Check with your child’s doctor or paediatric dietician about safe dairy alternatives.

Calcium and dairy allergy

Dairy products are generally the main source of calcium in a child’s diet. Children with dairy allergies will need to get their calcium from other sources.

Your child’s doctor or dietitian may recommend calcium supplements or calcium-fortified soymilk products. You can also see a dietician who can help ensure your child gets enough calcium to grow well.

Infant formula and dairy allergy

Babies with dairy allergies should not have formula made from cows' milk or other types of dairy, like goat's milk. Soy-based infant formula can be suitable for babies allergic to dairy if they are not allergic to soy. 

Rice-based formulas can be used for babies with allergies to dairy and soy.

Special infant formulas are made for babies with dairy and soy allergies that your doctor can prescribe if your baby cannot have a dairy or soy formula.

Infant formula labelled hypo-allergenic is inappropriate for babies with dairy allergies because it often contains dairy milk proteins. Speak to your doctor or dietician if you are unsure.

Dairy, food labels and eating out

It is important to always check the package and ingredient list of all foods your child eats.

In Australia, allergens are shown in bold each time they appear in an ingredient list. Packaged foods may have a warning on the label that "may contain traces of dairy".

This means the food is made in a facility that also makes foods that contain dairy. 

Talk to your child’s doctor about whether these foods are safe.

Always tell the staff that your child has a dairy or cow's milk allergy when eating out. This will help you find safe foods and avoid contamination. 

If you cannot confirm that food does not contain dairy, it is safest for your child to avoid it.

Education

The most important thing you can do is support your child in avoiding dairy in their diet. You can also educate your child, family, and friends about allergies, reactions, and what to do in an emergency.

Parents of younger children will need to read ingredient lists and learn to find dairy in foods and drinks.

Older children can be supported in learning to read ingredient lists and find dairy in foods. 

This can help keep children safe and encourage them to be more independent and confident about their diet and health as they grow.

Disclaimer

This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.


© Sydney Children’s Hospitals Network 2024