So many foods are made with milk and milk products these days that people with milk allergies have to pay attention to what's in just about everything they eat. And a milk allergy is not the same as lactose intolerance — some people with food allergies can become suddenly and severely ill if they eat or even come in contact with the food they're allergic to.

Some foods that contain milk are obvious, like pizza. But others, like baked goods, may not be so obvious. Plus, teens need calcium and vitamin D, which milk has lots of, because their bones are still growing. So what should a person who's allergic to milk do? Read on to find out.

What Happens With a Milk Allergy?

Food allergies involve the body's immune system, which normally fights infection. When someone is allergic to a particular food, the immune system overreacts to proteins in that food.

People who are allergic to cow's milk react to one or more of the proteins in it. Curd, the substance that forms chunks in sour milk, contains 80% of milk's proteins, including several called caseins (pronounced: kay-seenz). Whey (pronounced: way), the watery part of milk, holds the other 20%. A person may be allergic to proteins in either or both parts of milk.

Every time the person eats these proteins, the body thinks they are harmful invaders. The immune system responds by kicking into high gear to fend off the "invader." This causes an allergic reaction, in which chemicals like histamine are released in the body.

The release of these chemicals can cause someone to have the following problems:

• wheezing
• trouble breathing
• coughing
• hoarseness
• throat tightness
• stomachache
• vomiting
• diarrhea
• itchy, watery, or swollen eyes
• hives
• red spots
• swelling
• a drop in blood pressure

Milk allergy is like most food allergy reactions: It usually happens within minutes to hours after eating foods that contain milk proteins.

Although it's not common, milk allergies can cause a severe reaction called anaphylaxis. Anaphylaxis may begin with some of the same symptoms as a less severe reaction, but then quickly worsen. A person might have trouble breathing, feel lightheaded, or pass out. If it's not treated, anaphylaxis can be life threatening.

Milk allergy is often confused with lactose intolerance because people can have the same kinds of things happening to them (like stomach pains or bloating, for example) with both conditions. But they're not related:

• Milk allergy is a problem involving the immune system.
• Lactose intolerance involves the digestive system (which doesn't produce enough of the enzyme needed to break down the sugar in milk).

How Can Doctors Tell It's a Milk Allergy?

If your doctor suspects you might have a milk allergy, he or she will probably refer you to an allergist or allergy specialist for further testing. The allergy specialist will ask you questions. These may cover things like how often you have the reaction, the time it takes between eating a particular food and the start of the symptoms, and whether any family members have allergies or conditions like eczema and asthma.

The allergy specialist may perform a skin test on you. This test involves placing liquid extracts of milk protein on the forearm or back, pricking the skin a tiny bit, and waiting to see if a reddish, raised spot forms, indicating an allergic reaction.

You may need to stop taking anti-allergy medications (such as over-the-counter antihistamines) or prescription medication 5 to 7 days before the skin test because they can interfere with the results. Most cold medications as well as some antidepressants may also affect skin testing. Check with the allergist's office if you are unsure about what medications need to be stopped and for how long.

Some doctors might also take a blood sample and send it to a lab where it will be mixed with some of the suspected allergen and checked for IgE antibodies.

These types of tests are used for diagnosing what doctors call a fast-onset type of milk allergy. But for people whose allergic reactions to milk develop more slowly, skin and blood tests are not as helpful.

In these cases doctors try to diagnose the person using a food challenge. The person is told not to eat or drink anything made with milk for a period of time — usually a few weeks. Then, during the challenge, the person eats foods containing milk under a doctor's close supervision. If symptoms come back after eating milk products, it's a pretty sure bet the person has a milk allergy.

How Is It Treated?

To treat a milk allergy, the person who is allergic needs to completely avoid any foods that contain milk or milk products.

Avoiding milk involves more than just leaving the cheese off your sandwich. If you are allergic to milk, you need to read food labels carefully and not eat anything that you're not sure about. It's a good idea to work with a registered dietitian to develop an eating plan that provides all the nutrients you need while avoiding things you can't eat.

If you have a severe milk allergy — or any kind of serious allergy — your doctor may want you to carry a shot of epinephrine (pronounced: eh-puh-neh-frin) with you in case of an emergency. Epinephrine comes in an easy-to-carry container about the size of a large marker. It's easy to use — your doctor will show you how.

If you accidentally eat something with milk in it and start having serious allergic symptoms, like swelling inside your mouth, chest pain, or difficulty breathing, you can give yourself the shot right away to counteract the reaction while you're waiting for medical help. Always call for emergency help (911) when using epinephrine. You should make sure your school and even good friends' houses have injectable epinephrine on hand, too.

Keeping epinephrine on hand at all times should be just part of your action plan for living with a milk allergy. It's also a good idea to carry an over-the-counter antihistamine as this can help alleviate allergy symptoms in some people. Antihistamines should be used in addition to the epinephrine and not as a replacement for the shot.

If you've had to take an epinephrine shot because of an allergic reaction, then you should go immediately to a medical facility or hospital emergency room so they can give you additional treatment if you need it. Up to one third of anaphylactic reactions can have a second wave of symptoms several hours following the initial attack. Therefore, you might need to be observed in a clinic or hospital for 4 to 8 hours following the reaction.

Living With a Milk Allergy

It may be challenging to eliminate milk from your diet, but it's not impossible. Because most people don't get enough calcium in their diets even if they do drink milk, many other foods are now enriched with calcium, such as juices, cereals, and rice and soy beverages. But before you eat or drink anything calcium enriched, make sure it's also dairy free.

Milk and milk products can lurk in strange places, such as processed meats. Chocolate is another product that may contain dairy — so be sure to check the label before you eat it.

Manufacturers of foods sold in the United States must list on their labels whether a food contains any of the most common allergens. This means that you should be able to find statements like these somewhere on the label: "contains milk ingredients," "made with milk ingredients," or "processed in a facility that also processes milk products."

This new labeling requirement makes it a little easier than reading the ingredients list — instead of needing to know that the ingredient "hydrolyzed casein" comes from milk protein, you should be able to tell at a glance which foods to avoid. But it's still a good idea to get to know the "code words" for milk products when you see them in the ingredients of a food.

Some ingredients and foods that contain milk are:

• casein, calcium casein, casein hydrolysate, magenesium casein, potassium casein, rennet casein, sodium casein
• dairy products like cheese, yogurt, milk, pudding, sour cream
• butter, butter flavoring, butter fat, butter oil, artificial butter flavor
• lactalbumin, lactoalbumin phosphate, lactaglobulin, lactose
• margarine
• non-dairy creamers
• whey, whey hydrolysate

Vegan foods are made without animal products, such as eggs or milk. You can buy vegan products at health food stores. Be careful to read the labels of soy cheeses, though. They may say "milk-free" but could contain milk protein.

For your sweet tooth, soy- or rice-based frozen desserts, sorbets, and puddings are good substitutes for ice cream (as long as you're not allergic to soy), as are ice pops. For baking, milk substitutes work as well as milk and some come out better. Dairy-free margarine works as well as butter for recipes and spreading on your bagel.

Try 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 may have been used to fry something that contains milk.

People are usually understanding when it comes to food allergies — nobody wants to risk your health. When eating out, order the simplest foods and ask the waitstaff detailed questions about menu items. At a friend's house, explain your situation and don't be embarrassed to ask questions if you're staying for a meal.

Having a milk allergy doesn't mean you can't still enjoy eating. In fact, some people think that some of the milk substitutes — like vanilla soy milk — taste better than regular cow's milk. As with any specialized diet, you'll probably find that avoiding milk gives you the opportunity to explore and discover some great foods that you'd never have found otherwise!

Reviewed by: Archana Mehta, MD, and Sheelagh M. Stewart, RN, MPH
Date reviewed: October 2011