Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 mimicking Kawasaki disease (Kawa-COVID-19): a multicentre cohort

Abstract

Background: Current data suggest that COVID-19 is less frequent in children, with a milder course. However, over the past weeks, an increase in the number of children presenting to hospitals in the greater Paris region with a phenotype resembling Kawasaki disease (KD) has led to an alert by the French national health authorities.

Methods: Multicentre compilation of patients with KD in Paris region since April 2020, associated with the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ('Kawa-COVID-19'). A historical cohort of 'classical' KD served as a comparator.

Results: Sixteen patients were included (sex ratio=1, median age 10 years IQR (4·7 to 12.5)). SARS-CoV-2 was detected in 12 cases (69%), while a further three cases had documented recent contact with a quantitative PCR-positive individual (19%). Cardiac involvement included myocarditis in 44% (n=7). Factors prognostic for the development of severe disease (ie, requiring intensive care, n=7) were age over 5 years and ferritinaemia >1400 µg/L. Only five patients (31%) were successfully treated with a single intravenous immunoglobulin (IVIg) infusion, while 10 patients (62%) required a second line of treatment. The Kawa-COVID-19 cohort differed from a comparator group of 'classical' KD by older age at onset 10 vs 2 years (p<0.0001), lower platelet count (188 vs 383 G/L (p<0.0001)), a higher rate of myocarditis 7/16 vs 3/220 (p=0.0001) and resistance to first IVIg treatment 10/16 vs 45/220 (p=0.004).

Conclusion: Kawa-COVID-19 likely represents a new systemic inflammatory syndrome temporally associated with SARS-CoV-2 infection in children. Further prospective international studies are necessary to confirm these findings and better understand the pathophysiology of Kawa-COVID-19. Trial registration number NCT02377245.

Keywords: cytokines; inflammation; outcome and process assessment, health care.

Figure 1

Clinical features of Kawa-COVID-19 patients. (1A) Chest CT scan (lung window) of a 12-year-old girl with Kawasaki disease and SARS-CoV-2 infection showing diffuse peripheral ground-glass opacities in both lungs. (1B-1E) Mucocutaneous lesions in a 4.5-year-old boy with Kawasaki disease and SARS-CoV-2 infection: Non-purulent conjunctivitis (1B), maculo-papular rash (1C), dry cracked lips (1D) and orchitis (1E).

Figure 2

Main clinical features of Kawa-COVID-19 from the Paris region cohort, n=16 patients. In red: higher frequencies than classical Kawasaki disease.