Clinical overview and outcome in a cohort of children with polyarteritis nodosa

Objective: Polyarteritis nodosa (PAN) is a rare vasculitis in childhood and poor information is known about its long-term outcome. Our aim was to describe the clinical features, at onset and during the disease course, of childhood- onset PAN and identify a potential correlation with persistent organ damage and worse outcome in a cohort of paediatric patients with a confirmed diagnosis of PAN. Methods: A retrospective collection of demographic and clinical data of 52 Caucasian children diagnosed with PAN, fulfilling the EULAR/PRES diagnostic criteria, recruited from eight paediatric rheumatologic centres and one transition unit, was performed. A statistical correlation was made between clinical involvement at onset or during the overall disease course and patients' final outcome. Results: Data from 52 patients (31 males, 21 females) were collected: their mean age at onset was 7.9 years (median 6.3) and mean follow-up period was 6.2 years (median 5.4). At the last follow-up visit, 27 patients (51.9%) were off therapy in clinical remission, 17 (32.7%) were in clinical remission while on medication, and 6 (11.6%) had a persistent or relapsing disease course. Two patients (3.8%) deceased because of severe cerebral involvement. Cranial nerve palsy during the disease course was significantly correlated with a worse prognosis (p=0.011). The presence of nephrogenic hypertension at onset and seizures during the disease course were significantly associated with the development of irreversible organ damage (p= 0.040 and 0.011, respectively). Conclusion: Childhood PAN is a severe disease with substantial risk of long-term morbidities. In our cohort of patients the worst outcome was significantly correlated with renal and neurological involvement.