Their findings, just published in Scientific Reports, could point the way to specialty products for people who suffer from cow milk allergies, particularly young children. Cow milk is a common cause of food allergy in infants, affecting one in 50 children, persisting in some into adulthood. Symptoms can range from mild to life-threatening. The scientists focused on the allergen beta-lactoglobulin (BLG), which forms a large part of the allergic reactions 2-3% of infants have to cow milk.