A review of pediatric vasculitis with a focus on juvenile polyarteritis nodosa.

Systemic polyarteritis nodosa (PAN) is a vasculitis characterized and defined by necrotizing inflammatory changes in medium and/or small arteries. Children and adults with vasculitis differ in the relative frequency of some clinical manifestations and concomitant diseases. The European League against Rheumatism (EULAR)/Pediatric Rheumatology European Society (PRES) working group has proposed a classification of childhood vasculitis. With support from EULAR, the Pediatric Rheumatology International Trials Organization (PRINTO), and PRES, a formal statistical validation process, which included large-scale, web-based data collection, was undertaken. I now propose a set of criteria for systemic juvenile PAN that combines a modified mix of the EULAR/PRES criteria and the EULAR/PRINTO/PRES criteria. Cutaneous juvenile PAN is characterized by the presence of cutaneous features with no systemic involvement. The common cutaneous manifestations include cutaneous nodules and livedo racemosa. Our research group previously established an algorithm for the differential diagnosis of primary cutaneous vasculitis. We have recently developed a new version of that algorithm to diagnose vasculitis with cutaneous manifestations from a dermatologic point of view. Treatment of systemic juvenile PAN is based on a combination of corticosteroids and immunosuppressant agents. The clinical course of cutaneous juvenile PAN is generally benign.