ABSTRACT
Background: Children develop severe COVID-19 much less often than adults. However, a small proportion of children present with a complication, known as a multisystem inflammatory syndrome (MIS-C) sometimes associated with admission to an intensive care unit or death. Clinical presentation and consequences of MIS-C are still unclear. The aim of our study is to assess the features of MIS-C and its consequences on a child's health. Method: An observational longitudinal study of children and adolescents hospitalised from May 17 to October 26, 2020, with MIS-C to Morozovskaya Children's City Clinical Hospital, Moscow Department of Health Care, Moscow, Russia. Results: 37 children with MIS-C (meeting WHO, CDC, or RCPCH criteria) were hospitalised. The median age was 6 years (interquartile range 3.3-9.9 years), and 22 patients (59.5%) were male. The most common symptoms on admission were fever (97.3%), fatigue (86.5%), scleritis (85%), oral mucosal inflammation (83.8%), rash (70.3%), tachycardia (51.4%), nausea (51.4%), bilateral conjunctivitis (43.2%), cervical lymphadenopathy (43.2%). The most common laboratory abnormalities detected during hospitalization were elevated CRP (100%), ferritin (100%), D-dimer (89.19%), CRP (86.49%), platelets (85.49%), hypoalbuminemia (100%) and anemia (95.59%). EchoCG abnormalities were present in 6 (16.2%) children with evidence of myocardial dysfunction, 5 (13.5%)-pericarditis, and 3 (8.1%) with a coronary anomaly. The median time from discharge to the first follow-up was 15 days (interquartile range, 14-18 days) to the second follow-up was 47 days (interquartile range, 41-52 days). At the first follow-up, 7/33 (21.21%) children had at least 1 symptom, of whom 5 (15.15%) reported fatigue. At the second follow-up, only 1 child reported a symptom (rash). The normalisation of laboratory values and EchoCG findings was noted in all the children. Conclusion: In spite of the MIS-C severity, the tendency to fast regression of symptoms and laboratory and instrumental indexes is traced, which suggests recovery of children and adolescents from MIS-C without long-term consequences. Further long-term follow-up of patients with MIS-C is necessary since data on long-term health outcomes are limited.