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. This study sought to analyze the characteristics, treatment, and outcomes in patients with COVID‐19–associated pediatric vasculitis (excluding KD‐like vasculitis in MIS‐C). Methods: The inclusion criteria were as follows: 1) age <18 years at vasculitis onset; 2) evidence of vasculitis; 3) evidence of SARS–CoV‐2 exposure; and 4) ≤3 months between SARS–CoV‐2 exposure and vasculitis onset. Patients with MIS‐C were excluded. The features of the subset of patients in our cohort who had COVID‐19–associated pediatric IgA vasculitis/Henoch Schönlein purpura (IgAV/HSP) were compared against a pre‐pandemic cohort of pediatric IgAV/HSP patients. Results: Forty‐one patients (median age 8.3 years; male to female ratio 1.3) were included from 14 centers and 6 countries. The most frequent vasculitis subtype was IgAV/HSP (n = 30). The median duration between SARS–CoV‐2 exposure and vasculitis onset was 13 days. Involvement of the skin (92.7%) and of the gastrointestinal system (61%) were the most common manifestations of vasculitis. Most patients (68.3%) received glucocorticoids, and 14.6% also received additional immunosuppressive drugs. Remission was achieved in all patients. All of the patients with IgAV/HSP in our cohort had skin manifestations, while 18 (60%) had gastrointestinal involvement and 13 (43.3%) had renal involvement. When we compared the features of this subset of 30 patients to those of a pre‐pandemic pediatric IgAV/HSP cohort (n = 159), the clinical characteristics of fever and renal involvement were more common in our COVID‐19–associated pediatric IgAV/HSP cohort (fever, 30% versus 5%, respectively [P < 0.001]; renal involvement, 43.3% versus 17.6%, respectively [P = 0.002]). Recovery without treatment and complete recovery were each less frequent among our COVID‐19‐associated pediatric IgAV/HSP patients compared to the pre‐pandemic pediatric IgAV/HSP cohort (recovery without treatment, 10% versus 39%, respectively [P = 0.002]; complete recovery, 86.7% versus 99.4%, respectively [P = 0.002]). Conclusion: This is the largest cohort of children with COVID‐19–associated vasculitis (excluding MIS‐C) studied to date. Our findings suggest that children with COVID‐19–associated IgAV/HSP experience a more severe disease course compared to pediatric IgAV/HSP patients before the pandemic. [ABSTRACT FROM AUTHOR]