What is milk allergy?

Coffee is being poured into a glass of milk with ice cubes

Cow’s milk allergy is the most common food allergy in babies and young children. It’s also one of the most common food allergies in adults.

People with an allergy to cow’s milk may also be allergic to milk from other animals, for example sheep or goat’s milk. Non-dairy alternatives, such as soy milk can cause allergies too. But this is less common. In this article we’ll focus on dairy milk allergy, what symptoms to look out for and how it can be treated.

Milk allergy or lactose intolerance, what’s the difference?

Milk allergy and lactose intolerance are not the same thing. People with a milk allergy experience symptoms because their immune system mistakes milk proteins for a threat. To defend itself the body produces Immunoglobulin E (IgE) antibodies that activate whenever they encounter milk.

People with lactose intolerance aren’t able to fully digest the sugar in milk (lactose) because they lack lactase. This is an enzyme produced by cells in the lining of the small intestine. You need lactase to digest lactose.

It’s possible to mistake one condition for the other because they share similar digestive symptoms, including diarrhea. An allergist can help you to identify if you have either.

What are the symptoms of a milk allergy?

The symptoms of milk allergy you experience depend on the type of allergy you have. Milk allergies fall into two groups IgE and non-IgE. In this article we focus more on the IgE type.

  • IgE allergies: These are caused by IgE antibodies and symptoms tend to occur almost immediately or within in a very short amount of time.
  • Non-IgE allergies: These are caused by other cells in the immune system and may take up to 48 hours to develop. These symptoms are similar to milk intolerance.

What are the different
types of allergies?

Woman on her laptop reading about different types of allergy. She wants to know more about her symptoms

Immediate symptoms of milk allergy tend to be IgE mediated 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 black skin
  • 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

Symptoms that are non-IgE mediated typically take longer to develop and include:

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

If your milk allergy is caused by IgE antibodies, it may cause a severe allergic reaction called anaphylaxis. Symptoms of anaphylaxis can be similar to immediate symptoms of milk allergy. Because anaphylaxis is a medical emergency it requires urgent medical treatment.

Signs and symptoms of anaphylaxis include:

  • Skin can be flushed or pale, and may feel itchy with hives
  • Diarrhea, feeling or being sick
  • Low blood pressure (hypotension)
  • Swelling of the tongue or throat
  • Weak and rapid pulse
  • Airways tightening, which may cause wheezing and trouble breathing
  • Dizziness or fainting

Occasionally people experience these symptoms if they exercise after consuming milk products or other foods they’re allergic to. This is called food dependent exercise related anaphylaxis.

Woman sitting down experiencing stomach cramps from milk allergy

Could you have
another food allergy?

Emergency treatment for anaphylaxis

Epinephrine is the main medication used to counteract anaphylaxis. It’s another name for the hormone adrenaline. Your healthcare provider will prescribe it in the form of an auto-injector if they think you’re at risk of a severe allergic reaction.

It’s important to carry two auto-injectors with you everywhere in case a single dose is not enough. Also, show family and friends how it works so they know what to do in the event of an emergency. After using an auto-injector you should go to hospital in case of a delayed secondary reaction.

Wearing an allergy necklace or bracelet is also a good idea, as it lets people know how to help you in an emergency.

Milk allergy and food labels

The most effective way to prevent allergic reactions is to avoid milk and milk proteins. So it’s important to read food labels very carefully. Helpfully, there are also apps that can scan barcodes and read the ingredients for you.

The two main proteins that cause cow’s milk allergy are casein and whey. These proteins can be hard to avoid because they’re used in processed foods. You may also need to familiarize yourself with other terms used to describe milk-containing ingredients.

Milk allergy: prevention tips

Follow these tips to reduce your risk of exposure to milk:

  1. Question ingredients when eating out: Contact the restaurant beforehand to let them know you have an allergy. Also, mention your allergy while ordering and after the food is served. Self-service food counters should be avoided due to the risk of cross-contamination.
  2. Take care when at home: Keep milk-free food separate to avoid cross-contamination. Clean kitchen surfaces, cutlery, pots and pans with disposable wipes as allergens can remain on sponges. Wash your hands before eating and always eat at the table.
  3. When travelling plan in advance: Inform the airline and request a dairy-free meal. Or take your own food. This works for long bus and train journeys too. Use wipes to clean tables and armrests. Always keep allergy medicine accessible. And take spares. Have your prescription and a doctor’s note with you in case you need to show it to someone. An app can help you to identify allergens abroad.
  4. Create a food allergy action-plan This is particularly important for children in school. If your child is old enough, make them aware that lots of foods and drinks can contain milk, even when it’s not obvious.
  5. Share your food allergy status: Traces of allergens can linger in saliva. Avoid sharing food, drinks and cutlery with others, even close family members. And do tell a new romance about your milk allergy before a kiss.
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How do I find out if I have a milk allergy?

Speak to your healthcare provider if you’re concerned. They will ask about your symptoms and family history. It can help to keep a food diary to log your symptoms.

Your healthcare provider may want to perform a skin prick test or blood test to confirm a diagnosis. The first involves putting a small amount of the proteins found in milk on your arm, carefully pricking the skin underneath it and waiting for a reaction. If the results are inconclusive they may take a blood sample to look for IgE antibodies.

Milk allergy can either be IgE or non-IgE related. IgE reactions typically happen immediately while non-IgE reactions can take up to 48 hours to develop. Both involve the immune system. Non-IgE food allergies are harder to diagnose because they won’t show up in blood test results.

Your healthcare provider may suggest an oral food challenge. This involves drinking increasing amounts of milk while being monitored for a reaction. Depending on your medical history, they may want to carry out an internal examination with a camera. This is called an endoscopy.

How do you treat a milk allergy?

Don’t change your diet without talking to your healthcare provider first. Treatment plans normally include a combination of avoiding milk and treating symptoms when this hasn’t been possible.

Quote Image

Did you know around 80% of children are likely to outgrow milk allergy before they turn 16.

Antihistamine is a common treatment for mild allergic symptoms. It helps to block the effects of histamine, which your body releases when it feels under attack. Your pharmacist can tell you about the different types available without a prescription.

Can a milk allergy go away on its own?

Around 80% of children are likely to outgrow a milk allergy before they turn 16 years old. Symptoms are most likely to persist in children who have high levels of cow’s milk antibodies in their blood. Blood tests that measure these antibodies can help your allergist to determine if a child is likely to outgrow a milk allergy or not.

Young children who are allergic to fresh milk but can tolerate baked milk may outgrow a milk allergy sooner than those who react to baked milk. Consuming baked milk could build up tolerance or lead to allergy resolution over time. Speak to your healthcare provider before trying this.

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