Multisystem Inflammatory Syndrome in children: tools for a timely diagnosis in the Emergency Department from an Italian Multicenter Survey

Objective: To assess the most frequent clinical features of Multisystem Inflammatory Syndrome in children (MIS-C) at presentation to the Emergency Department (ED) in a large multicenter cohort of patients, in order to define useful tools for a timely diagnosis. Methods: Clinical and laboratory characteristics were retrospectively reviewed for 210 MIS-C patients from 18 Italian pediatric EDs. We assessed correlations between clinical and laboratory parameters and compared features of patients of different age (≤5 years and >5 years). Results: Fever was the main presenting symptom (100%), followed by conjunctivitis (46%), abdominal pain (44%), vomit (41%) and diarrhea (39%). Forty-nine percent of children presented to the ED in critical or nearly critical conditions. A higher prevalence of mucocutaneous involvement was found in younger children (69% versus 47%, p 5 years (62% versus 85%, p <0.05). Higher values of inflammatory markers (C-Reactive Protein, Ferritin, and Fibrinogen), Troponin T and Brain Natriuretic Peptide were related to abnormal echocardiography ( p <0.05). No significant differences were detected in laboratory parameters between the two age groups, apart from ferritin, fibrinogen and troponin T, which resulted significantly lower in children ≤5 years. Conclusions: Apart from fever, most common MIS-C manifestations at presentation to the ED are conjunctivitis, abdominal pain, vomit and diarrhea. Younger children more frequently present with mucocutaneous involvement, while gastrointestinal manifestations are more common in older patients. These findings should be considered when MIS-C is suspected in the ED, in order to achieve a timely recognition of the condition.