People who aren't allergic to milk may think it's easy to control a milk allergy. You just say "no" to milk, ice cream, and cheese, right? But so many foods are made with milk and milk products that parents of kids with a milk allergy have to pay attention to just about everything their kids eat.
The American Academy of Allergy, Asthma, and Immunology estimates that up to 2 million, or 8%, of kids in the United States are affected by food allergies, and that eight foods account for 90% of food allergy reactions: milk, eggs, peanuts, wheat, soy, fish, shellfish, and tree nuts.
Help your milk-allergic child avoid adverse reactions by knowing which foods and ingredients to avoid.
What Is a Milk Allergy?
Milk allergy usually first occurs when infants are given cow's milk-based formula or are exposed to cow's milk in the mother's diet through her breast milk. Between 2% and 3% of babies and toddlers are affected by milk allergy.
Milk contains proteins, carbohydrates (such as sugars), fats, minerals, and vitamins. Casein is the principal protein in cow's milk, accounting for about 80% of the total milk proteins. Casein is what makes up the curd that forms when milk is left to sour. The remaining 20% of cow's milk proteins are contained in the whey, the watery part that's left after the curd is removed.
The proteins in milk are what cause allergic reactions in some people. A person may be allergic to proteins in either the casein or the whey parts of milk and sometimes even to both.
There are two major types of milk allergy reactions: rapid onset and slower onset. The rapid type of reaction comes on suddenly (within seconds to hours after ingesting the milk or milk product) with symptoms that can include wheezing, vomiting, hives, angioedema (fluid collection in body tissues that causes swelling), and anaphylaxis (a sudden and severe whole body reaction).
The slower-onset reaction is the more common type. Symptoms develop over a period of hours to days after ingesting the milk and may include loose stools (possibly containing blood), vomiting, fussiness or irritability, and failure to gain weight and grow normally. This type of reaction is more difficult to diagnose because the same symptoms may occur with conditions other than allergy. Most kids will outgrow milk allergy by 2 to 3 years of age.
People often confuse a milk allergy with lactose intolerance, but they are not the same thing. Differences include:
- Milk allergy is a reaction of the immune system to proteins in milk and milk products; lactose intolerance is caused by an inability of the body to break down the milk sugar lactose.
- The signs and symptoms of a milk allergy usually appear in early infancy; lactose intolerance is very rare in the first years of life.
- Milk allergy can affect the digestive system as well as other systems in the body, such as skin and airways; lactose intolerance affects digestion only, causing bloating, gas, or loose bowel movements after drinking milk or eating dairy products.
- In rare cases, milk allergy can be life-threatening; lactose intolerance is not life-threatening, and people with lactose intolerance can often consume small amounts of milk without experiencing any symptoms.
Signs and Symptoms
When kids who are allergic to milk drink it or eat something made with milk or milk products, they could have any of the following symptoms. (But remember that these symptoms may also occur with many other illnesses, so check with your child's doctor to confirm or rule out a milk allergy.)
- excessive fussiness or irritability
- crampy abdominal pain, vomiting, or diarrhea
- spots or streaks of blood or mucus in stools
- skin rash
- recurrent wheezing, cough, stuffy or runny nose, colds, or sinusitis
- failure to thrive (poor weight gain and growth)
Some kids with the rapid-onset type of reaction may experience a sudden, potentially severe allergic reaction called anaphylaxis that can involve various systems in the body (such as the skin, respiratory tract, gastrointestinal tract, and cardiovascular system). Anaphylaxis can cause a person's blood pressure to drop, airways to narrow, and tongue to swell, resulting in serious breathing difficulty, loss of consciousness and, in some cases, even death. Anaphylaxis is much more common in peanut, nut, and shellfish allergies than in milk allergy.
In case of an emergency, kids with a milk allergy should have access to a shot of epinephrine, which is only available with a doctor's prescription. It comes in an easy-to-carry, single-shot container that looks like a pen (it's commonly known as an EpiPen). If a milk-allergic person accidentally consumes milk or milk products and has an anaphylactic reaction, a shot of epinephrine can be given to help counteract it. Your doctor can give you instructions on how to use and store the epinephrine injection pen; it's essential that you familiarize yourself with the procedure.
Kids who are mature enough to carry their own epinephrine shot (allergists say this is usually around age 12 or 13) should keep one readily available at all times (check with schools about rules governing the carrying of medicines). If your child is younger than 12, talk to the school nurse and your child's teacher about keeping one on hand in case of an emergency. Also make sure that epinephrine pens are available at your home, as well as at the homes of friends and family members.
Your doctor may encourage your child to wear a medical alert bracelet. It's also a good idea to carry an over-the-counter antihistamine, which can help alleviate allergy symptoms in some people. But antihistamines should be used in addition to the EpiPen and not as a replacement for the shot.
Kids who have had to take an epinephrine shot should go immediately to a medical facility or hospital emergency room, where additional treatment can be given if needed. Up to one third of anaphylactic reactions can have a second wave of symptoms several hours following the initial attack, so the child might need to be observed in a clinic or hospital for 4 to 8 hours following the reaction.
Feeding a Milk-Allergic Infant
If your baby is found to have the rapid-onset type of cow's milk protein allergy, your doctor will probably recommend switching to a soybean-based formula. Soy-based formulas contain the proteins found in soybeans rather than those found in cow's milk. Most of the same vitamins and minerals found in cow's milk-based formulas are also found in soy-based formulas, making the nutritional value of the two formulas basically equal. Only 8% to 15% of infants with rapid-onset type of allergy also have an adverse reaction to soy formulas.
If the switch to soy formula doesn't stop the symptoms, the infant usually will be switched to a hypoallergenic formula. The protein in hypoallergenic formulas has been specially treated to make it less likely to trigger an allergic reaction.
About half of all infants with the more common slow-onset type of milk allergy are also allergic to soy formulas, in which case a hypoallergenic formula is recommended. Hypoallergenic formulas can be up to three times more expensive than standard cow's milk or soy formulas, so be sure your child is among the 2% or 3% of kids with a diagnosed milk protein allergy before you make the switch. Talk to your doctor about which formula is best for your child.
Two major types of hypoallergenic formulas are available:
- extensively hydrolyzed formulas, in which the milk proteins have been broken down or "predigested," making it less allergenic than the whole proteins in regular formulas
- amino acid-based infant formulas, which contain protein in its simplest form and may be recommended if your baby's condition doesn't improve with a switch to a hydrolyzed formula
(Note that formulas labeled as partially hydrolyzed protein formulas are not considered hypoallergenic.)
It is possible that your doctor may suggest switching from cow's milk-based formula to exclusive breastfeeding. Breastfeeding a milk-allergic infant should be done under the close supervision of a registered dietitian because a strict diet must be followed to ensure adequate intake of nutrients while eliminating cow's milk protein. Because the cow's milk protein in the dairy products in a mother's diet can cross over to breast milk, all dairy products must be eliminated from her diet. Working with a dietitian can help a nursing mother find alternative sources of calcium and other vital nutrients found in dairy products.
Feeding a Milk-Allergic Older Child
Once a child is beyond the formula stage and is eating and drinking real foods and liquids, avoiding milk and milk products can become a real challenge.
A registered dietitian or nutritionist can recommend and monitor a milk-free diet that is nutritionally sound. He or she will provide a list of alternative foods that will substitute the nutrients — such as calcium, riboflavin, and vitamin D — your child needs.
In addition to not drinking milk, people who are allergic to it have to be diligent about reading labels on — and asking questions about — everything they want to eat. Beginning in 2006, food makers are required to clearly state on labels whether a food contains milk or milk products. But the new law only applies to foods labeled after the start of 2006, so there may still be products on the shelves that don't say whether the food contains the allergen.
Milk may be hidden in many foods, even those you'd never dream of, such as processed meats, brown sugar flavoring, canned tuna, and chocolate. The long list of other foods and ingredients to avoid includes:
- butter and related products (including artificial butter flavor, butter fat, butter solids, butter oil, buttermilk, and natural butter flavor)
- caramel color or caramel flavoring
- casein products and caseinates (including ammonium, calcium, iron, magnesium, potassium, rennet, sodium, and zinc caseinates)
- cottage cheese
- cream and cream curds
- fat replacers such as Opta and Simplesse
- flavorings and natural flavorings (including Bavarian cream flavoring, brown sugar flavoring, caramel flavoring, coconut cream flavoring, some seasonings and natural flavors for meat and poultry, binding agents, fillers, natural egg flavor, canned fish, seasoned and ranch-style potato and tortilla chips, and seasoned french fries)
- goat's milk (contains proteins similar to those in cow's milk)
- high-protein flour and other types of added protein (particularly the kind found in "high-energy" foods, which often contain milk protein)
- hydrolysates (including hydrolyzed casein and milk protein)
- lactose (and other products that begin with lact including lactalbumin, lactalbumin phosphate, lactate, lactic acid starter culture, lactoferrin, lactoglobulin, and lactulose)
- milk in all forms (including condensed milk, dry milk, dry milk solids, evaporated milk, low-fat milk, nonfat or skim milk, milk derivative, milk fat, milk powder, milk protein, milk solids, malted milk, and powdered milk)
- sour cream, sour cream solids, and sour milk solids
- whey and whey products (including delactosed whey, demineralized whey, whey powder, whey protein concentrate, and whey protein hydrolysate)
Many nondairy foods can be substituted for milk or milk products. Be aware, however, that just because a food is labeled "nondairy," it does not necessarily mean that it is milk free. Even a "milk-free" label can be misleading. For example, some soy cheeses claim to be milk free but may still contain milk protein. That's why it's always important to read all food labels when you have a milk-allergic child.
When dining out, encourage your child to order the simplest foods, and ask the waitstaff detailed questions about menu items. Fried and battered foods should be avoided; even if the batter doesn't contain milk products, the oil used to fry the foods may have been used to fry something that did contain milk. Cross-contamination can especially be a problem at buffets, where spoons often go in and out of various bowls that may contain milk or milk products.
Cross-contamination can easily occur at home too. Make sure you use separate knives for spreading butter and making sandwiches, and use separate bowls for chips, crackers, or other foods that people might touch after touching a piece of cheese, dip, or other milk product.
Some good alternatives to milk and milk products include:
- for baking: milk substitutes work as well as milk, and some come out better. Fruit juice also works in baking, but you should then reduce the amount of added sugar. For milk used simply as a liquid, substitute water or rice milk. Dairy-free margarine, vegetable shortening, or soy butter (if your child tolerates soy) can be substituted for real butter. Pureed tofu works well as a thickener.
- for breakfast: calcium-enriched rice or soy milk (if soy is tolerated)
- for sandwiches and snacks: vegan products, such as vegan cheese, are sold at health food stores and made without eggs or milk
- for treats: soy-based (again, if soy is tolerated) or rice-based frozen desserts, sorbets, puddings, and ice pops
Teachers, school nurses, and childcare providers also should be told about your child's milk allergy. Try to get lunch menus in advance to help your child choose wisely or pack a homemade lunch if cross- contamination cannot be avoided.
Having a milk allergy doesn't mean your child can't enjoy eating. In fact, some people think some of the milk substitutes — like vanilla soy milk — taste better than regular cow's milk. In fact, your child will probably find that avoiding milk offers the opportunity to discover some great foods he or she would never have found otherwise.
Reviewed by: Julie Metos, MPH, RD, CDE
Date reviewed: October 2003