Cow’s milk allergy is the most common food allergy in infants and young children. Approximately 2-3% of children younger than 3 years old are allergic to milk. Milk allergy accounts for about 1/5 of all childhood food allergies. Usually, milk allergy presents in the first year of life. The majority of people who are allergic to cow’s milk are also allergic to goat’s and sheep’s milk.
There are different kinds of milk “allergy”. Below are the most common:
1.) IgE-mediated milk allergy: This is an allergy mediated by the allergic antibody in your blood. Symptoms usually start within minutes of eating cow’s milk but can be as late as 2 hours later. Symptoms can involve hives, abdominal pain, vomiting, diarrhea, SOB, coughing, wheezing, increased runny nose, and lightheadedness. In infants they can be very sleepy or fussy as well. These reactions can range from mild to life-threatening. The majority (~80%) will outgrow cow’s milk allergy by the age of 16. While rare, for some people, milk allergy can persist into adulthood.
2.) Food Protein-Induced Enterocolitis Syndrome (FPIES): This is a food allergy that is not mediated by the allergic antibody. It is most common in infants. FPIES usually presents as severe vomiting and diarrhea within 2-4 hours of eating cow’s milk containing products. The symptoms are so severe that patients can develop severe dehydration leading to shock in some cases. If a patient has chronic exposure to cow’s milk, the symptoms can be a little more subtle including failure to thrive (or grow normally), spitting up, and diarrhea. FPIES can arise from other foods but cow’s milk is one of the most common offending allergens.
3.) Food Protein-Induced Proctocolitis: This is also not mediated by the allergic antibody. Food protein-induced proctocolitis usually presents by 6 months of age and is characterized by bloody-streak, mucousy, loose stools. Cow’s milk is one of the most common triggers for this. Nearly all infants will be able to tolerate cow’s milk by age one.
What is the difference between a food allergy and a food intolerance?
A milk allergy is mediated by your immune system. It occurs when your immune system reacts to cow’s milk like it is a dangerous invader, such as a cold or the flu. A milk allergy can be life-threatening. A milk intolerance is usually a lactose intolerance. In lactose intolerance, your body cannot digest the sugar in milk, specifically lactose because they do not have the enzyme to do so (lactase). Lactose intolerance is not mediated by the immune system and is not life threatening.
Your allergist will be able to tell what kind of reaction you have to milk by taking a detailed history and with allergy skin testing. Then they can help you come up with the appropriate treatment plan. Call us if you want to be seen for a possible milk allergy.