People often confuse milk protein allergy with lactose intolerance. While some symptoms are similar, milk protein allergy and lactose intolerance are caused by different mechanisms in the body and managed differently. Although milk allergies and intolerances can occur at any age, lactose intolerance is more common in adults.
Lactose Intolerance
Lactose intolerance results from an inability or insufficiency to digest lactose, a sugar found in cow's milk and other dairy products. Lactose intolerance occurs when a person is deficient in lactase, an enzyme that breaks down lactose. Lactase deficiency can be genetic or occur from injury to the small intestine, according to the National Digestive Diseases Information Clearinghouse. People who are lactose intolerant typically are able to tolerate small amounts of milk products.
Milk Protein Allergy
Milk allergies involve the immune system and typically occur in babies and young children. According to the Mayo Foundation for Medical Education and Research, milk allergies result when the immune system recognizes milk proteins as being harmful, resulting in allergic reactions. The Nemours Foundation notes that about 2 to 3 percent of infants have a milk allergy, which is less common in breast-fed babies. Children who have an allergy to cow's milk typically also have adverse reactions to sheep's, goat's and sometimes soy milk.
Symptoms
Although milk protein allergies and lactose intolerance are different conditions, they do share some of the same symptoms. Abdominal pain or cramping, nausea or vomiting, and diarrhea are symptoms common to both. However, according to the Mayo Foundation for Medical Education and Research, under some circumstances, a milk protein allergy can result in more severe symptoms, such as airway constriction or a sudden drop in blood pressure, resulting in shock.
Differences
According to the National Digestive Diseases Information Clearinghouse, lactose intolerance usually develops after age 2, commonly in adulthood or late adolescence. Although milk allergies are common in children, the Mayo Foundation for Medical Education and Research notes that most children outgrow milk allergies by the time they turn 3 years old.
Recommendations
Lactose intolerance and milk protein allergies can be managed to help prevent unpleasant side effects. Individuals who are lactose intolerant may be able to tolerate dairy products that are lower in lactose, such as hard cheeses, yogurt or lactose-free milks. To ease symptoms when consuming lactose-containing products, lactase enzyme tablets or drops are available.
Children with a milk protein allergy should avoid milk proteins to help prevent potentially dangerous allergic reactions. Medications are available to help reduce some symptoms associated with milk allergies. Injectable epinephrine may be used to help reduce severe allergic reactions.
