The Cow's Milk Related Symptom Score: The 2022 Update.

CoMiSS® was developed 7 years ago to increase the awareness of health care professionals towards the possibility that symptoms presented by infants could be related to cow's milk. While CoMiSS was conceived mostly on theoretical concepts, data is now available from 25 clinical trials. Based on this extensive research using the tool since 2015, we aim to propose an updated CoMiSS. The evidence was reviewed, debated and discussed by 10 experts, of whom seven were part of the original group. The panel concluded that the cut-off previously proposed to indicate the likelihood that symptoms may be cow's milk related should be lowered from ≥12 to ≥10. Data in healthy infants > 6 months are missing. Since the Brussels Infant and Toddlers Stool Scale (BITSS) was recently developed for non-toilet trained children, the Bristol Stool Scale was changed to the BITSS without changing the impact of stool characteristics on CoMiSS. Overall, CoMiSS raises awareness that symptoms might be cow's milk related. New studies are needed to determine if the change in cut-off and other small adaptions improve its sensitivity and specificity. Data for CoMiSS is still needed in presumed healthy infants between 6 and 12 months old. There may also be regional differences in CoMiSS, in healthy infants as well as in those with cow's milk allergy. Finally, we emphasize that CoMiSS is an awareness tool and not a diagnostic test.