RESUMEN
OBJECTIVE: To characterize pediatric patients who had been diagnosed with polyarteritis nodosa (PAN) through necrotizing vasculitis of the small and mid-size arteries or those with characteristic findings on angiograms data were collected. STUDY DESIGN: Pediatricians were asked to classify their patients into one of the four suggested groups for juvenile PAN. Twenty-one pediatric centers worldwide participated with 110 patients. RESULTS: The girl:boy ratio was 56:54, with a mean age of 9.05 +/- 3.57 years. The cases were classified as: 33 (30%) cutaneous PAN; 5 (4.6%) classic PAN associated with hepatitis B surface antigen (HBs Ag); 9 (8.1%) microscopic polyarteritis of adults associated with antineutrophil cytoplasmic antibodies (ANCA); and 63 (57.2%) systemic PAN. Cutaneous PAN was disease confined to the skin and musculoskeletal system. All patients with HBs Ag-associated classic PAN were diagnosed with renal angiograms. Antiviral treatment was administered in most cases. Microscopic PAN patients had pulmonary-renal disease, in combination or separately. ANCA was present in 87%, and 2 patients progressed to end-stage renal failure. Patients classified with systemic PAN had multiple system involvement, almost all had constitutional symptoms, and all had elevated acute phase reactants. Corticosteroids and cyclophosphamide were the first choices of immunosuppressive treatment. The overall mortality was 1.1%. CONCLUSIONS: There were remarkable differences among pediatric patients with PAN, with different clinical manifestations and overall better survival and lower relapse rates when compared with adults.