Multisystem Inflammatory Syndrome in Children Presenting as Acute Appendicitis

Abstract

Background The majority of multisystemic inflammatory syndrome in children (MIS-C) patients presented with gastrointestinal symptoms. To draw attention to association of MIS-C and acute appendicitis, we reported a number of patients presented with localized symptoms as appendicitis but later diagnosed as MIS-C. The main goal of this study was to point out that localized presentation of MIS-C, and the secondary outcome was to compare 2 different treatment modalities of MIS-C. Methods The patients admitted to intensive care units of 2 tertiary hospitals, with diagnosis of MIS-C and accompanying clinically or radiologically suspected or confirmed appendicitis, were included. Data were retrospectively analyzed. The patients were examined in 2 groups as intravenous immunoglobulin (IVIG)-only and combined therapy. The combined therapy was defined as at least 2 immunomodulatory treatments of which included IVIG, steroid, Anakinra, and plasmapheresis. Results Between June 2020 and December 2020, 9 patients were enrolled in the study. The mean age was 8.7 ± 3.4 years. All patients had delayed diagnosis because of investigations focusing on abdominal pathologies such as appendicitis. Four patients had typical ultrasonographic findings of appendicitis and 2 were complicated with perforation. All patients had cardiovascular compromise accompanying at least 1 more organ dysfunction. In the IVIG only group, the median lymphocyte count was 480 cells/mm3 and the median levels of ferritin, C-reactive protein (CRP), procalcitonin, and interleukin 6 were 955 pg/mL, 17.4 mg/dL, 33.9 ng/mL, and 136.3 pg/mL, respectively. In the combined therapy group, the median lymphocyte count was 1200 cells/mm3 and the median levels of ferritin, CRP, procalcitonin, and interleukin 6 were 1650 pg/mL, 28 mg/dL, 47.8 ng/mL, and 56.7 pg/mL, respectively. The median pediatric risk of mortality 3 and pediatric logistic organ dysfunction scores of the combined therapy group were higher than IVIG-only group. The IVIG-only patients were more lymphopenic at presentation (P = 0.014), while ferritin, CRP, and procalcitonin levels of combined therapy group were higher than IVIG-only group (P = 0.376, P = 0.181, and P = 0.346, respectively). The mean length of stay in pediatric intensive care unit of combined therapy group was shorter than IVIG-only group. Conclusions Multisystemic inflammatory syndrome in children should be kept in mind in the differential diagnosis of patients with localized gastrointestinal symptoms, such as acute appendicitis. Early diagnosis and proper treatment of MIS-C may have a critical role in the patient's outcome.