The characteristics of patients with COVID-19-associated pediatric vasculitis: an international, multicenter study.

OBJECTIVE: COVID-19 associated pediatric vasculitis other than Kawasaki disease (KD)-like vasculitis in multisystem inflammatory syndrome in children (MIS-C) is very rare. We aimed to analyze the characteristics, treatment and outcome in COVID-19-associated pediatric vasculitis (excluding KD-like vasculitis in MIS-C).

METHODS: The inclusion criteria were as follows: 1) <18 years at vasculitis onset; 2) evidence of vasculitis; 3) evidence of SARS-CoV-2 exposure; 4) ≤3 months between SARS-CoV-2 exposure and vasculitis onset. Patients with MIS-C were excluded.

RESULTS: Forty-one patients (median age 8.3 years; M/F=1.3) were included from 14 centers and six countries. The most frequent vasculitis subtype was IgA vasculitis/Henoch Schönlein purpura (IgAV/HSP) (n=30). The median duration between SARS-CoV-2 exposure and vasculitis onset was 13 days. Skin (92.7%) and gastrointestinal (61%) involvements were the most common manifestations of vasculitis. Most patients (68.3%) received corticosteroids; while 14.6% used additional immunosuppressive drugs. Remission was achieved in all. All IgAV/HSP patients had skin manifestations while 18 (60%) and 13 (43.3%) had gastrointestinal system and renal involvement, respectively. When we compared the features of these patients with those of a pre-pandemic pediatric IgAV/HSP cohort (n=159), fever (30% vs. 5%; p<0.001) and renal involvement (43.3% vs. 17.6%; p=0.002) were more common, while recovery without treatment (10% vs. 39%; p=0.002) and complete recovery (86.7% vs. 99.4%; p=0.002) were less frequent among COVID-19-associated IgAV/HSP patients.

CONCLUSION: This is the largest cohort of children with COVID-19 associated vasculitis (excluding MIS-C). Our findings suggest a more severe disease course in COVID-19-associated pediatric IgAV/HSP patients compared to pre-pandemic patients. This article is protected by copyright. All rights reserved.