Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19: A Case Series Experience in a Tertiary Care Hospital of Southern Turkey.

Objective: Aim of the study is to assess the clinical characteristics and treatment outcomes of multisystem ınflammatory syndrome in children (MIS-C) associated with COVID-19.

Study Design: The study comprised 52 children with MIS-C admitted to University of Health Sciences Adana City Training and Research Hospital pediatric wards from September 2020 to April 2021. Demographic characteristics and clinical data were retrospectively collected from patient files.

Results: Median age of patients was 9 (5-13) years. Fever (92.3%), abdominal pain (76.9%), rash (48.1%) and vomiting (48.1%) were the most common presenting symptoms. Fever duration was 8 (4.25-10) days in overall. Depressed left ventricular ejection fraction was found in 17.3% of patients. At admission, elevated levels of C-reactive protein, procalcitonine, erythrocyte sedimentation rate, D-dimer and ferritin were found in 98.1%, 96.2%, 75%, 84.6% and 69.2% of the patients, respectively. Lymphopenia, hyponatremia and hypoalbuminemia were found in 76.9%, 59.6% and 42.3% of the patients. Intravenous immunoglobulin was used in 96.2%, corticosteroids in 71.2% and anakinra in 3.8% of the patients. In total, 28.8% of the patients were admitted to pediatric intensive care unit and 17.3% received vasopressor support. Median duration of hospital length of stay was 12.5 days. Comorbidities were present in 19.2% of the patients. No mortality was recorded.

Conclusions: While being rare and treatable, MIS-C is the ugly and mysterious face of the COVID-19 pandemic for children. The increasing number of MIS-C cases shows that this phenomenon is more common than thought. Comprehensive studies are required to understand the pathogenesis of the disease and determine the treatment regimens clearly.

Lay Summary: While being rare and treatable, multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 is the ugly and mysterious face of the COVID-19 pandemic for children. MIS-C is now thought to be a post-infectious (SARS-CoV2) hyperinflammatory disease secondary to an abnormal immune response, rather than a complete obscurity. The increasing number of MIS-C cases and new case series reports from all over the world show that MIS-C is more common than thought. Despite our increasing experience, we may encounter a new finding every day in MIS-C patients. Therefore, we want to contribute to literature by presenting the MIS-C cases we treated in our clinic in detail. We have experienced that MIS-C patients can apply with similar but also different and unique characteristics. In case of delayed diagnosis or treatment, morbidity and mortality rates may increase. Therefore, the level of awareness and knowledge of all physicians, especially those dealing with pediatric patients, about MIS-C should be increased. Although the early effects of MIS-C are known, we don't have enough information about the long-term consequences yet. Comprehensive studies are required to understand the pathogenesis of the disease and determine the treatment regimens clearly.