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Milk Allergy

What Is Milk Allergy?

Milk allergy is the most common food allergy in young kids, affecting about 2%–3% of those younger than 3 years old. Many kids outgrow it, but some are allergic for a lifetime.

A milk allergy can cause a range of symptoms, from mild to severe.

Allergy to milk is sometimes confused with lactose intolerance. Both can cause problems after drinking milk, but they are very different and unrelated. Lactose intolerance is annoying and can cause discomfort, but it is not life-threatening. Milk allergy, though, can make someone suddenly and severely ill, and can be life-threatening. That's why milk and other dairy products must be completely avoided if your child has a milk allergy.

If you're not sure if your child has an intolerance or an allergy, speak with your doctor.

What Happens in a Milk Allergy?

When someone is allergic to milk, the body's immune system, which normally fights infections, overreacts to proteins in the milk. Every time the person drinks or eats milk or other dairy products, the body thinks these proteins are harmful invaders and releases chemicals like histamine . This can cause symptoms such as:

  • wheezing
  • trouble breathing
  • coughing
  • hoarseness
  • throat tightness
  • stomachache
  • vomiting
  • diarrhea
  • itchy, watery, or swollen eyes
  • hives
  • swelling
  • a drop in blood pressure, causing lightheadedness or loss of consciousness

Allergic reactions to milk can differ. Sometimes the same person can react differently at different times. Milk allergy can cause a severe reaction called anaphylaxis, even if a previous reaction was mild. Anaphylaxis might start with some of the same symptoms as a less severe reaction, but can quickly get worse. The person may have trouble breathing or pass out. More than one part of the body might be involved. If it isn't treated, anaphylaxis can be life-threatening.

How Is an Allergic Reaction to Milk Treated?

If your child has been diagnosed with a milk allergy (or any kind of serious food allergy), keep two epinephrine auto-injectors available in case of an emergency.

An epinephrine auto-injector is a prescription medicine that comes in a small, easy-to-carry container. It's easy to use. Your doctor will show you how. Kids who are old enough can be taught how to give themselves the injection. If they carry the epinephrine, it should be nearby, not left in a locker or in the nurse's office.

Every second counts in an allergic reaction. If your child starts having serious allergic symptoms, like swelling of the mouth or throat or trouble breathing, give the epinephrine auto-injector right away. Also give the epinephrine auto-injector right away if your child's symptoms involve two different parts of the body, like hives with vomiting. Then call 911 or take your child to the emergency room. Your child needs to be under medical supervision because even if the worst seems to have passed, a second wave of serious symptoms can happen.

It's also a good idea to carry an over-the-counter (OTC) antihistamine for your child, as this can help treat mild allergy symptoms. Use antihistamines after — not as a replacement for — the epinephrine shot during life-threatening reactions.

What Else Should I Know?

To prevent allergic reactions to milk, your child must avoid any foods that contain milk, milk products, or milk proteins. Read food labels to see if a food contains milk.

Milk may be found in unexpected places, such as processed meats, canned tuna, and baked goods, so it's important to read labels on all foods, even ones that are not dairy foods.

Makers of foods sold in the United States must state in understandable language whether foods contain any of the top eight most common allergens, including milk. The label should list "milk" in the ingredient list or say "Contains milk" after the list. For detailed information about foods to avoid, visit Food Allergy Research & Education (FARE).

Some foods look OK from the ingredient list, but while being made they can come in contact with a food your child is allergic to. This is called cross-contamination. Look for advisory statements such as "May contain milk," "Processed in a facility that also processes milk," or "Manufactured on equipment also used for milk." These are cross-contamination warnings, but manufacturers are not required to list them.

You can contact the company directly to see if a product contains milk. Check the company's website for this information or email a company representative.

Food makers sometimes change ingredients, so always read the food labels.

Milk Alternatives

Milk from other animals (such as sheep, goats, and buffalo) are not good alternatives for those with a cow's milk allergy because the proteins are similar.

But many other milk-free alternatives are available, including ones that are fortified with calcium and vitamin D. The allergist can tell you which milk substitute is best for your child.

Eating Away From Home

Cross-contamination can happen in restaurants when milk or milk products get into a food product. The staff might use the same surfaces and utensils (like knives, cutting boards, or pans) to prepare both dairy products and other foods. This is particularly common in fast-food restaurants, so some people find it safer to avoid these restaurants altogether.

Buffet-style restaurants also pose a cross-contamination risk, with cheeses and salad dressings dripping over non-dairy food platters. When eating at restaurants, it may be best to avoid fried foods or foods with batter on them. Even if the batter doesn't contain milk products, the oil used to fry the foods might have been used to fry something else that contains milk.

When your child eats in a restaurant or at a friend's house, find out how foods are cooked and exactly what's in them. It can be hard to ask a lot of questions about cooking methods, and to trust the information you get. If you can't be sure that a food is milk-free, it's best to bring safe food from home.

Also talk to the staff at school about cross-contamination risks for foods in the cafeteria. It may be best to pack lunches at home so you can control what's in them.

If your child will be eating at a restaurant, take these precautions:

  • Tell the restaurant wait staff that your child has a milk allergy.
  • Carry a personalized "chef card" for your child, which can be given to the kitchen staff. The card details your child's allergies for food preparers. Food allergy websites provide printable chef card forms in many different languages.
  • Don't eat at a restaurant if the manager or owner seems uncomfortable about your requests for a safe meal.

Reviewed by: Michelle Clark, MD;Hillary B. Gordon, MD
Date Reviewed: 03-09-2018