Kawasaki disease and multisystem inflammatory syndrome in children. Differences, and similarities in a pediatric center in Mexico.

Objective: To evaluate the differences and similarities in clinical picture, laboratory findings and outcomes between children’s with Kawasaki Disease (KD) versus multisystem inflammatory syndrome (MIS-C). Methods: We conducted a retrospective, comparative study from children with Kawasaki Disease (KD) hospitalized in Sinaloa Pediatric Hospital from January 1, 2004, to March 31, 2020, and patients with multisystem inflammatory syndrome (MIS-C) according with World Health Organization (WHO) case definition criteria between May 1, 2020 and May 31, 2021. Demographic characteristics, epidemiological data, clinical features, laboratory findings, type of treatment and clinical outcomes were compared among both groups. Results: Eighty-one patients were included (62 patients with KD and 19 with MIS-C). several clinical and laboratory differences were found among these two entities. Median age was lower in KD vs. MIS-C (25 vs 79 months). Mucocutaneous features (93.5 vs. 63.2%): Oral changes (83.9 vs. 63.2%) and extremity changes (77.4 vs. 57.9%). Neurological symptoms (63.1 vs. 11.2%), kidney involvement (52.6 vs. 16.1%). Lymphocyte count (2.07 + 2.03 vs. 4.28 + 3.01/mm3), platelet count (197.89 + 187.51 vs. 420.37 + 200.08/mm3). KD vs. MIS-C types of Treatment: IVIG (96.8 vs. 94.7%), systemic steroids (4.82 vs. 94.7%), IVIG resistance (19.4 vs. 15.8). Finally, mortality in KD was 0% and 5.3% in MIS-C. Conclusion: Significant differences such as severity of clinical presentation with multi-organ involvement and worst inflammatory response were found more frequently in MIS-C group than KD group, requiring more fluid replacement, use of inotropic agents and higher steroids dosages. Also, mortality rate was higher in patients with MIS-C than patients with KD.