Childhood-onset
polyarteritis nodosa (PAN) is a rare and systemic necrotising
vasculitis in children affecting small- to medium-sized arteries. To date, there have been only a few reports because of its rarity. Thus, we aimed to investigate the clinical manifestations, laboratory findings, treatment, and long-term outcomes in patients with childhood-onset PAN and to evaluate the usefulness of the paediatric
vasculitis activity score (
PVAS). We retrospectively analysed the data of nine patients with childhood-onset PAN from March 2003 to February 2020. The median ages at symptom onset, diagnosis, and follow-up duration were 7.6 (3-17.5), 7.7 (3.5-17.6), and 7.0 (1.6-16.3) years, respectively. All patients had constitutional symptoms and
skin manifestations, while five exhibited Raynaud's phenomenon. Organ involvement was observed in one patient. The median
PVAS at diagnosis was 7 (range: 2-32).
Prednisolone was initially used for induction in all patients, and other drugs were added in cases refractory to
prednisolone. All patients survived, but three patients with high
PVAS at diagnosis experienced irreversible sequelae, including intracranial haemorrhage and digital
amputation. In conclusion, early diagnosis and treatment may minimise sequelae in patients with childhood-onset PAN. This study suggests that high
PVAS score at diagnosis may be associated with poor prognosis.