Cow’s milk allergy (CMA) is one of the most common food allergies worldwide in early childhood. Many CMA guidelines exist, aimed at describing the symptom presentation and diagnostic criteria, but in spite of this, both under and over diagnosis has been described in clinical practice. The primary reason for this, is that many of the commonly described symptoms impacting on the skin, gastrointestinal tract and respiratory tract are the similar to symptoms experienced with other diagnoses. Both over and under diagnosis carry a nutritional risk, including faltering growth and micronutrient deficiencies and impact on the quality of life of families. There is also a possible impact on the healthcare system, with increased healthcare visits and over-prescribing of hypoallergenic formula. Tools to support recognition and the diagnostic process were highlighted in a study in 2015. The Cow’s Milk Related Symptom Score (CoMiSS™) was developed for a study in 2014 and evolved with the help of a group of experts into a tool that has been assessed in 25 original studies, originating from many different countries. This tool was developed to raise awareness and support healthcare professionals in improving the patient journey from symptoms presentation to diagnosis.