To the Editor: We read with interest the retrospective study reported by Dhaliwal et al. [1] about the severity and cardiac involvement in multisystem inflammatory syndrome in children. It is an interesting study; however, we wish to discuss the following aspects that need further clarification:

Firstly, as elaborated in the results section, 53 patients satisfied the WHO-MIS-C criteria, out of which 5 were diagnosed as having dengue and the rest were MIS-C. Considering that this was a multicentric study, what were the other tropical infections that were ruled out? The number of cases with enteric fever, scrub typhus, leptospirosis, enterovirus infection, etc. could have been mentioned [2]; also the number of cases with dual seropositivity or coinfections. The case of diabetic ketoacidosis as a presentation of MIS-C needs elaboration, as, due to high seropositivity rates, many diseases may often mimic MIS-C.

Secondly, as organ dysfunction was used as criteria to differentiate mild, moderate, and severe, it would be good to know which organ dysfunction score/criterion was used to quantify severity (PELOD 2/p SOFA) or any other such score. It is interesting to note that WHO-MIS-C criteria suggest any two of the following to label a patient as MIS-C— (1) rash/conjunctivitis, (2) shock, hypotension, (3) myocardial dysfunction, (4) coagulopathy, (5) acute GI problems [3], how then were mild cases defined as having minimal organ dysfunction if they were labelled MIS-C.

Thirdly, as mentioned in the discussion, those in the mild/moderate disease group may have had Kawasaki disease overlap phenotype, whereas those in the severe group, may have presented with myocarditis. The deciding factor would have been the ejection fraction or the shortening fraction, which could have been mentioned in the characteristics of mild/moderate MIS-C versus severe cases.

We commend the authors for shedding light on their interesting observations. However, a discussion on the above aspects will be insightful.