Milk is the most common food allergy for children under 5, but new research says many cases are not diagnosed.

In a study released on Friday, researchers found that milk allergy affects over half of 1-year-olds who have food allergies, accounts for 40% of food allergies for kids 1 to 2, and is the most common overall food allergy for children under 5.

“The general public needs to be more aware of milk allergies. They think it’s all peanut,” Dr. Ruchi Gupta, a professor of pediatrics at the Northwestern school of medicine in Chicago and an author of the study, told NBC News. “We set out to build awareness so families can get the proper diagnosis.”