Identify the symptoms of milk allergies and how they differ from lactose intolerance.
Milk allergies are usually rare and controllable, but they can be deceptive because they are often confused with lactose intolerance. Milk allergies are most common in infants and children, but lactose intolerance can affect people of any age. The major difference between the two conditions is that a milk allergy causes a reaction in the immune system, while lactose intolerance is a result of a dearth of lactase, the enzyme that breaks down lactose (a sugar found in milk), in the small intestine.
Allergies develop when the body reacts to a normally benign substance as if it were an invader, producing an antibody called immunoglobulin E (IgE) in response to the "foreign" substance. The IgE antibodies attach to cells found in the blood, gastrointestinal tract, skin, nose, lungs and throat. The next time food that contains the allergen is ingested, the antibodies are triggered and symptoms like hives and vomiting appear.
Some people with milk allergies have near-instant reactions, while others may not develop any symptoms for a few hours or even days. Common symptoms include:
• Loose stools (possibly containing blood or mucus)
Other symptoms include:
• Skin rash
• Sinusitis (inflammation or infection of the sinuses)
• Diarrhea (possibly containing blood or mucus)
• Itchy bumps on the skin
• Abdominal cramps
• Runny nose
Physicians use several tests to determine whether a milk allergy is present. Medical history often has a significant bearing, as children of parents with allergies (including other food allergies as well as environmental allergies) are more likely to develop a milk allergy. Other information about the timing of the reaction, how much food was ingested and any medicines that may have alleviated symptoms will help the doctor determine the presence of a milk allergy. Sometimes doctors ask patients to keep a diet diary to determine whether reactions to a specific allergen are consistent.
Other possible measures include skin tests that can indicate whether antibodies respond to a particular food. Blood tests like RAST, ELISA and CAP-RAST can provide the physician with very specific information about the presence of food-specific IgE in the blood.
Children often outgrow food allergies by the age of six, but adults who develop them are usually allergic for life. The only way to avoid allergic reactions is to avoid the food that causes them. Milk contains two proteins, casein and whey, that can cause allergic reactions. People with milk allergies may be allergic to either or both. Knowing which protein is the offender will help allergy sufferers to avoid it in non-dairy foods like protein powder, chocolates and artificial butter flavors.
Approximately 2 to 3 percent of infants have an allergy to cow's milk, according to the National Institute of Allergy and Infectious Diseases. In infants, the most common symptoms (loose stools, colic, skin rashes, vomiting, gagging and refusing food) usually appear 7 to 10 days after consuming cow's milk. Less commonly, symptoms may appear soon after feeding and may include vomiting, wheezing, hives, bumps on the skin, irritability, swelling and bloody diarrhea. Very rarely, a severe allergic reaction known as anaphylaxis occurs. In this case, the affected infant requires immediate medical attention.
Formula-fed infants may be switched to soy-based or hypoallergenic formula. Breastfeeding mothers may have to restrict their dairy intake, as cow's milk proteins are passed through the mother's milk to the infant.
If you suspect that you or your child has a milk allergy, contact your doctor. Be prepared to provide your medical history, and consider starting a diet diary to collect details to provide to your physician.