Background: Cow's milk protein allergy (CMPA): The topic of definition still causes confusion among physicians. Words such as "allergy," "intolerance," and "hypersensitivity" are used interchangeably. The accepted definition of allergy is "a hypersensitivity reaction triggered by specific immunologic mechanisms". There is no such thing as "allergy to lactose" but rather lactose intolerance. The authors introduced the acronym "CoMiSS" (cow's milk-related symptom score).