Childhood- versus Adult-Onset Polyarteritis Nodosa Results from the French Vasculitis Study Group Registry.

OBJECTIVE: To investigate differences between childhood (cPAN)- and adult-onset polyarteritis nodosa (aPAN) patients.

METHODS: cPAN patients' clinical findings at onset and outcomes were compared to those of aPAN patients from the French Vasculitis Study Group registry matched for year of enrollment and initial systemic versus cutaneous disease. Their information on medications, disease activity and damage were collected. Kaplan-Meier relapse-free survival curves and the log-rank test were used to analyze cPAN versus aPAN differences for predefined outcomes.

RESULTS: Twenty-one children with systemic and 13 with cutaneous PAN were compared with 84 systemic- and 27 cutaneous-matched aPAN patients. Median follow-up exceeded 5 years for both groups. At study entry, mononeuritis multiplex was less frequent in systemic cPAN than systemic aPAN (P = 0.04), and purpura and myalgias were less frequent in cutaneous cPAN than cutaneous aPAN (P < 0.03). During follow-up, systemic cPAN relapsed more often than matched systemic aPAN (P < 0.0001), while relapse rates were similar for cutaneous disease (P > 0.05). Mostly minor relapses, predominantly involving the skin, occurred in all 4 groups. At last visit, damage accrual was comparable for cPAN and aPAN patients, but fewer systemic cPAN patients were treatment-free (15% versus 42%; P = 0.03). Two (6%) cPAN and 8 (7%) aPAN patients died.

CONCLUSION: Systemic PAN is equally severe in children and adults and carries a higher risk of relapse. The main cutaneous PAN features seem not to be influenced by age at disease onset.