Top Papers Of The Month

Multisystem Inflammatory Syndrome: An Evolving Understanding of a Complex Condition

AUTHOR:
Jessica Tomaszewski, MD
Nemours duPont Pediatrics

CITATION:
Tomaszewski J. Multisystem inflammatory syndrome: an evolving understanding of a complex condition. [published online July 14, 2020]. Consultant360.

 

Feldstein LR, Rose EB, Horwitz SM, et al; the Overcoming COVID-19 Investigators and the CDC COVID-19 Response Team. Multisystem inflammatory syndrome in U.S. children and adolescents. Published online June 29, 2020. N Engl J Med. doi:10.1056/NEJMoa2021680

 

Throughout the COVID-19 pandemic, the pediatric population has experienced less-severe disease burden overall. However, in April 2020, clinicians started describing children presenting with fever, inflammation, and cardiovascular shock. By May, the Centers for Disease Control and Prevention (CDC) issued a national health advisory to report on cases meeting criteria for multisystem inflammatory syndrome in children (MIS-C).

To further understand this rare but serious condition, Dr Feldstein and colleagues reviewed the epidemiology and clinical characteristics of 186 cases of MIS-C in surveillance states reported to the CDC from March 15, 2020, to May 20, 2020, as part of the Overcoming COVID-19 study.

The case definition included 6 criteria: serious illness requiring hospitalization, age younger than 21 years, at least 24 hours of fever, laboratory studies consistent with inflammation, multisystem organ involvement, and evidence of infection with SARS-CoV-2 (identified through polymerase chain reaction (PCR), antibodies, or known COVID-19 exposure). Particular attention was paid to the severity of cardiovascular involvement.

The median age was 8.3 years. Of the 186 cases, 131 patients (70%) had positive SARS-CoV-2 results from reverse transcription PCR or antibody testing, and a significant portion (73%) of those had been previously healthy. The majority (88%) of patients with MIS-C were hospitalized between April 16 and May 20, when the peak activity of COVID-19 was decreasing.

Almost all (92%) of the patients had involvement of the gastrointestinal system, with high percentages of cardiovascular system (80%), hematologic (76%), mucocutaneous (74%), and respiratory system (70%) involvement. Most of the patients (80%) received care in an intensive care setting, with 20% receiving mechanical ventilation. About half (48%) required vasoactive support, and 4 patients died.

From a review of laboratory studies, the majority of patients had an elevated erythrocyte sedimentation rate or C-reactive protein level, lymphopenia, hypoalbuminemia, elevated aminotransferase level, anemia, thrombocytopenia, and an elevated D-dimer level. Treatment often included immunomodulating therapies such as intravenous immune globulin (77%), glucocorticoids (49%), and interleukin-6 inhibitors (20%).

Dr Feldstein and colleagues also compared MIS-C to Kawasaki disease. MIS-C seems to affect adolescents and children older than 5 years of age and also has more frequent cardiovascular involvement. Fifteen patients in this study had documented coronary artery aneurysms, and 74 (40%) had Kawasaki disease-like features. Interestingly, the patients with Kawasaki disease-like features were also more likely to be less than 5 years of age. This highlights the importance that all patients with MIS-C should receive echocardiography scanning.

Overall, this condition is rare but has potentially serious implications for the pediatric community. Close monitoring and further data gathering must continue to create a greater understanding in these unusual times.