Diagnostic Criteria and Management of Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19

Essential Diagnostic Components

The American College of Rheumatology recommends diagnosing MIS-C using a tiered laboratory approach combined with clinical features and confirmed SARS-CoV-2 exposure, starting with screening labs and progressing to complete evaluation if initial markers are suggestive 1, 2, 3
A child must have any one of the following epidemiologic links to SARS-CoV-2: positive SARS-CoV-2 PCR test, positive SARS-CoV-2 serology, preceding illness resembling COVID-19, or close contact with confirmed or suspected COVID-19 case within the past 4 weeks 2, 3, 4, 5, 6
Clinical features must be present, including fever, multisystem involvement, and at least two of the following: mucocutaneous findings, gastrointestinal symptoms, cardiac manifestations, neurologic symptoms, or other features such as lymphadenopathy 1, 2, 3, 6

The initial screening labs should include CBC, CMP, ESR, CRP, and SARS-CoV-2 PCR and/or serologies 2, 3, 5, 6
If the initial screening labs are suggestive, a complete evaluation should be performed, including additional studies such as procalcitonin, cytokine panel, and coagulation studies 2, 3, 4, 5, 9

Children with MIS-C should be admitted for observation if they have abnormal vital signs, respiratory distress, neurologic deficits, evidence of renal or hepatic injury, or marked elevations in inflammation markers 1, 3, 7, 9
Immediate admission is required for children with shock, significant respiratory distress, neurologic changes, dehydration, or features of Kawasaki disease 1, 5, 6, 9

Children admitted with MIS-C require consultation with pediatric rheumatology, pediatric cardiology, pediatric infectious disease, pediatric hematology, and additional subspecialties as clinically indicated 1, 3, 7, 9

Echocardiogram should be performed at diagnosis, 7-14 days after presentation, and 4-6 weeks after presentation, with more frequent monitoring if LV dysfunction or coronary artery aneurysms are present 1, 8
EKG monitoring should be performed every 48 hours minimum while hospitalized, during follow-up visits, and continuously if conduction abnormalities are present 7, 8
Cardiac biomarkers such as BNP and troponin T should be trended until normalization 8