Prevention

There's no sure way to prevent a food allergy, but you can prevent reactions by avoiding the food that causes them. If you know you or your child is allergic to milk, avoid milk and milk products.

Read food labels carefully. Look for casein, a milk derivative, which can be found in some unexpected places, such as in some canned tuna, sausage or nondairy products. Question ingredients when ordering in restaurants.

Sources of milk

Obvious sources of allergy-causing milk proteins are found in dairy products, including:

• Whole milk, low-fat milk, skim milk, buttermilk
• Butter
• Yogurt
• Ice cream, gelato
• Cheese and anything that contains cheese
• Half-and-half

Milk can be harder to identify when it's used as an ingredient in processed foods, including baked goods and processed meats. Hidden sources of milk include:

• Whey
• Casein
• Ingredients spelled with the prefix "lact" — such as lactose and lactate
• Candies, such as chocolate, nougat and caramel
• Protein powders
• Artificial butter flavor
• Artificial cheese flavor
• Hydrolysates

Even if a food is labeled "milk-free" or "nondairy," it may contain allergy-causing milk proteins — so you have to read the label carefully. When in doubt, contact the manufacturer to be sure a product doesn't contain milk ingredients.

When eating out, ask how foods have been prepared. Does your steak have melted butter on it? Was your seafood dipped in milk before cooking?

If you're at risk of a serious allergic reaction, talk with your doctor about carrying and using emergency epinephrine (adrenaline). If you have already had a severe reaction, wear a medical alert bracelet or necklace that lets others know you have a food allergy.

Milk alternatives for infants

In children who are allergic to milk, breast-feeding and the use of hypoallergenic formula can prevent allergic reactions.

• Breast-feeding is the best source of nutrition for your infant. Breast-feeding for as long as possible is recommended, especially if your infant is at high risk of developing milk allergy.

• Hypoallergenic formulas are produced by using enzymes to break down (hydrolyze) milk proteins, such as casein or whey. Further processing can include heat and filtering. Depending on their level of processing, products are classified as either partially or extensively hydrolyzed. Or they may also be called elemental formulas.

  Some hypoallergenic formulas aren't milk based, but instead contain amino acids. Besides extensively hydrolyzed products, amino-acid-based formulas are the least likely to cause an allergic reaction.

• Soy-based formulas are based on soy protein instead of milk. Soy formulas are fortified to be nutritionally complete — but, unfortunately, some children with a milk allergy also develop an allergy to soy.

If you're breast-feeding and your child is allergic to milk, cow's milk proteins passed through your breast milk may cause an allergic reaction. You may need to exclude from your diet all products that contain milk. Talk to your doctor if you know — or suspect — that your child has milk allergy and develops allergy signs and symptoms after breast-feeding.

If you or your child is on a milk-free diet, your doctor or dietitian can help you plan nutritionally balanced meals. You or your child may need to take supplements to replace calcium and nutrients found in milk, such as vitamin D and riboflavin.