Les symptômes courants de l’allergie au lait peuvent inclure l’urticaire, le gonflement, la maladie et la respiration sifflante. Mais cela dépend si vous avez une hypersensibilité de type I ou de type IV.

La réaction allergique immédiate que vous connaissez le mieux est l’APLV de type I. Elle fait intervenir les anticorps de l’immunoglobuline E (IgE). Le type IV fait appel à une autre partie du système immunitaire et a tendance à se manifester plus lentement.

Le lait de vache est l’une des allergies alimentaires les plus courantes chez les bébés et les jeunes enfants. Le lait d’autres animaux peut également causer des réactions allergiques. Lisez ce qui suit si vous pensez que vous ou votre enfant présentez des symptômes d’allergie aux protéines de lait de vache. Nous décrirons ce qu’il faut rechercher et comment traiter l’APLV, quel que soit son type.

Symptoms tend to happen almost immediately and can include:

• A raised, itchy rash on the skin (hives) – sometimes skin is irritated and itchy but not raised. It may look red on pale skin, or like the surrounding color on darker skin types
• Itching or tingling around the mouth or lips
• Swelling of the face, mouth, throat or other parts of the body
• Feeling or being sick (vomiting)
• Shortness of breath or coughing
• Wheezing

Non IgE milk allergy symptoms could take up to two days to develop and can include:

• Stomach cramps
• Diarrhea
• Fresh blood in stools (especially in babies)
• Colic in babies– episodes of unexplained crying, irritability and screaming usually without an obvious cause

Antihistamine can help to block the effects of histamine, which the body releases when it feels under threat. It’s a common treatment for mild allergic symptoms from food. Ask your pharmacist for advice. Some types are available without a prescription.

The allergic reaction involves other cells in the immune system and the effect is similar to that of lactose intolerance (when you can’t fully digest lactose, the sugar in milk).

Non IgE milk allergy symptoms could take up to two days to develop and can include:

• Stomach cramps
• Diarrhea
• Fresh blood in stools (especially in babies)
• Colic in babies– episodes of unexplained crying, irritability and screaming usually without an obvious cause

Antihistamine can help to block the effects of histamine, which the body releases when it feels under threat. It’s a common treatment for mild allergic symptoms from food. Ask your pharmacist for advice. Some types are available without a prescription.

Yes, an IgE milk allergy can cause a serious allergic reaction called anaphylaxis. This tends to involve more than one part of your body. It can affect your airways, breathing and circulation and often but not always your skin. It can also happen if you exercise after contact with milk allergens (food dependent exercise related anaphylaxis).

Cow’s milk is one of the most common causes of anaphylaxis in children. This type of life-threatening allergic response tends to affect more than one part of the body and is an emergency at any age. Call for an ambulance if you recognize these symptoms.

Epinephrine is another name for the hormone adrenaline. Your doctor is likely to prescribe it in the form of an auto-injector if they think you’re at risk of anaphylaxis as a milk allergy reaction.

Carry two auto-injectors with you at all times in case a single dose is not enough. Family and friends need to know how it works so they can help you in an emergency. After using an auto-injector go to hospital for observation even if you feel better, in case of a delayed secondary reaction.

Sometimes milk allergy symptoms last into adulthood. But around 80% of children may outgrow their allergy before age 16. Milk allergy symptoms are most likely to continue in children who have more cow’s milk antibodies in their blood.

Young children who are allergic to fresh milk but can tolerate baked milk, for instance in breads, crackers, cookies, cakes and muffins, may outgrow their allergy earlier than those who react to all milk products.

There are also breath and blood tests to identify lactose intolerance, which does not involve the immune system.

Consuming milk, even in a small amount, may trigger allergy symptoms. Eliminating it from your diet is essential. Read tips on how to do that in our article on food allergies.

You may also have to avoid milk from other four-legged animals such as sheep and goats because the proteins are similar. It is possible to react to alternative non-dairy milks such as soy but it’s less common and a separate food allergy.

Milk is one of the most common food allergens that's tricky to avoid. Many foods contain milk or may have come into contact with it. Always check with the manufacturer, food shop, restaurant or café if you’re worried you might be about to trigger your food allergy.

• Cow’s milk is used in many processed foods, from canned tuna to luncheon meat, hot dogs and sausages
• Cross-contamination is a risk at the deli where slicers may be used for both meat and cheese
• Butter can add flavor, which is why restaurants put it on top of steaks. But it’s invisible by the time it melts.

Some specialist food labels could make you feel safe if you get milk allergy symptoms. But what are they actually saying? 

• Non-dairy: This does not mean milk-free. On non-dairy products you may see casein or other milk proteins listed. Even milk may be listed. Frozen whipped toppings and creamers are often labeled as non-dairy.
• Milk-free: Check the label for hidden milk proteins.
• Dairy-free: This term may or may not mean that a product is free of milk. If in doubt, check the ingredients.
• Plant-based: These foods can contain animal products, including milk. Don’t assume it’s free of milk without checking the ingredients.
• Animal-free milk/dairy: This may contain a type of milk that does not come from animals but uses the DNA sequence from a cow in a process called fermentation. It’s best avoided by anyone with a milk allergy.
• Vegan: This term refers to foods and products that don’t contain ingredients from animals or byproducts that come from animals, such as eggs. Vegan foods shouldn’t contain milk but check the ingredients anyway.
• Kosher: These foods need to meet the requirements of Jewish law. They may contain small amounts of milk from cross-contamination.

There is no Health Canada-approved oral immunotherapy for milk allergy.

But a food ladder is another way of gradually building up tolerance to milk. It involves introducing thoroughly heated sources of milk, such as baked goods. Slowly you increase the quantity and move on to less processed foods. It’s an approach reserved for children considered most likely to outgrow their food allergy. Of course, any contact with a food allergen carries the risk of causing a severe systemic allergic reaction. So it must only be undertaken on the advice of your healthcare provider and with the utmost care.

Avoiding milk allergy symptoms usually means avoiding milk completely, from cows and maybe other animals. The allergens are similar so you may react to them too. Non-dairy milks can cause symptoms but this is less common.

Milk allergy symptoms vary from mild, often eased by antihistamine, to life-threatening anaphylaxis. The treatment for anaphylaxis is epinephrine administered immediately via auto-injector. Call an ambulance or go to hospital too. Speak with your doctor for advice about this and long-term treatment options.