Dairy Allergy and Foods

A dairy allergy is an immune reaction to the proteins in milk. It can cause a serious problem, with reactions ranging from stomach pain to full-blown anaphylaxis, a serious condition which requires immediate medical attention. It is easy to miss certain milk derivatives on food-ingredient lists if you don't know what to look for.

Milk

• Those with dairy allergies should avoid cow's milk in liquid form, and many may need to avoid goat's or sheep's milk, too. Reactions --- stomach upset, rashes, breathing problems, sinus problems and wheezing and coughing --- can occur within seconds for serious allergies or within hours in less severe cases.

Casein

• Milk contains a protein known as casein, which is likely to cause allergic reactions. Cheese contains high levels of casein; the harder the cheese, the more casein it contains. Those with a dairy allergy should avoid all cheeses and yogurts.

Whey

• Whey, the byproduct of cheese making, is a common protein additive in many foods. You might find it in products such as chips, margarine, microwave meals and even carob and soy products. People with lactose intolerance can usually digest whey, but those with true dairy allergies react to the protein.

Lactose

• Lactose intolerance is different from a dairy allergy. Those with dairy allergies can sometimes digest lactose. Still, many cannot, and dairy allergies and lactose intolerance often go hand-in-hand. Look for any mention of lactose, lactic acid, lactalbumin or generally anything with the word "lact."

Dairy-free Foods

• Watch out for so-called dairy-free or nondairy items. These may still contain trace amounts of milk, milk proteins or milk derivatives.