Cows' milk protein allergy (CMPA), also known as cows' milk allergy (CMA), is one of the most common food allergies in babies and young children. There are many symptoms associated with CMPA, but it can be easily managed with the correct diet, so getting a diagnosis is very important. The good news is that the majority of children who are allergic to cows' milk will outgrow this by the time they are 3 years old.