Characterization of primary vasculitis in pediatrics

Primary vasculitides are a group of diseases of unknown cause characterized by inflammation of the blood vessel walls. There are few published data at the national level. Objective: To determine the incidence and prevalence of primary vasculitis in the Chilean pediatric population and to describe the clinical characteristics, laboratory, treatment, and evolution. Patients and Method: Retrospective study that included patients with a diagnosis of primary vasculitis under 16 years of age, treated in a Pediatric Rheumatology clinic of a tertiary hospital in Santiago, Chile, between January 2015 and December 2019. Data was obtained from clinical records and a computer registry. The diagnoses were: IgA vasculitis (Henoch-Sch & ouml;nlein Purpura), Hemorrhagic Edema of Infancy , Kawasaki Disease (KD), Polyarteritis nodosa (PAN), Granulomatosis with polyangiitis (GPA), and Microscopic Polyangiitis (MPA). No cases of eosinophilic granulomatous with polyangiitis or Takayasu's arteritis were found in this sample. The variables analyzed were demographic characteristics, clinical manifestations, laboratory, images, biopsies, treatments, and evolution. Results: A total of 134 patients were analyzed. The overall incidence of primary vasculitis was 11 cases, and the prevalence was 21 cases per 100,000 patients under 16 years of age/year. IgA vasculitis accounted for 62.7%, KD for 31.3%, HEI for 2.2%, PAN for 1.5%, GPA for 1.5%, and MPA for 0.8%. Their clinical presentation varied according to the type of vasculitis. Conclusion: It is important to make known to the medical community the epidemiological data and clinical characteristics of these pathologies at the hospital and national level since they are not necessarily similar to other populations.