This study describes the incidence, associated clinical characteristics and outcomes of acute kidney injury in a pediatric cohort with COVID-19 and Multisystem Inflammatory Syndrome in Children (MIS-C). We performed a retrospective study of patients 18 years of age and under admitted to four New York hospitals in the Northwell Health System interned during the height of the COVID-19 pandemic, between March 9 and August 13, 2020. Acute kidney injury was defined and staged according to Kidney Disease: Improving Global Outcomes criteria. The cohort included 152 patients; 97 acute-COVID-19 and 55 with MIS-C associated with COVID-19. Acute kidney injury occurred in 8 with acute-COVID-19 and in 10 with MIS-C. Acute kidney injury, in unadjusted models, was associated with a lower serum albumin level (odds ratio 0.17; 95% confidence interval 0.07, 0.39) and higher white blood cell counts (odds ratio 1.11; 95% confidence interval 1.04, 1.2). Patients with MIS-C and acute kidney injury had significantly greater rates of systolic dysfunction, compared to those without (80% vs 49%). In unadjusted models, patients with acute kidney injury had 8.4 days longer hospitalizations compared to patients without acute kidney injury (95% confidence interval, 4.4-6.7). Acute kidney injury in acute-COVID-19 and MIS-C may be related to inflammation and/or dehydration. Further research in larger pediatric cohorts is needed to better characterize risk factors for acute kidney injury in acute-COVID-19 and with MIS-C consequent to COVID-19.

COVID-19 is the illness caused by infection with the novel coronavirus SARS-CoV-2. Although myalgia is common in adults, it has not been noted as a common symptom in children. There have been a few reported cases of COVID-19-associated rhabdomyolysis in adults. This case report describes a 16-year-old boy who presented with fever, myalgias, mild shortness of breath with exertion, and dark-colored urine. COVID-19 PCR was positive. His initial creatinine kinase (CK) level was 427,656 U/L. Serum creatinine was normal for age. He was treated with isotonic intravenous fluids containing sodium bicarbonate to maintain urine output of 100-200 mL/h and urine pH > 7.0. His serum creatinine remained normal throughout the hospital stay and he was discharged on hospital day 12 with a CK of 6526 U/L. To our knowledge, no pediatric cases of COVID-19-associated rhabdomyolysis have been previously reported. Adult cases of rhabdomyolysis have been reported and a few reports have noted patients with elevated CK levels without rhabdomyolysis. Given this pediatric case of COVID-19-associated rhabdomyolysis, pediatric clinicians should be aware of this complication and manage fluids appropriately in order to prevent acute kidney injury.

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pandemic has had shifting epicenters since its discovery in December 2019 in Wuhan, China. In the United States, New York City became an early hub, and now the virus continues its spread throughout the country. While the virus has had devastating effects on the elderly population, 1 data suggest that children are relatively spared. [2][3][4][5] In a report of over 70,000 COVID-19 cases from Wuhan, only 1% were diagnosed in children under 10 years of age, and another 1% in children aged 10-19. 4