A Case Report of Childhood Polyarteritis Nodosa: A Rare Vasculitic Disorder with Multisystem Involvement.

BACKGROUND: Childhood polyarteritis nodosa (cPAN) is a rare systemic necrotizing vasculitis affecting small- and medium-sized arteries. Its heterogeneous clinical manifestations often delay diagnosis, yet early recognition is essential to prevent organ damage. According to the EULAR/PRINTO/PRES criteria, diagnosis requires evidence of necrotizing vasculitis in medium- or small-sized arteries or characteristic clinical features such as skin involvement, myalgia, hypertension, or peripheral neuropathy. This case adds to the limited literature by presenting a severe multisystem form of cPAN in a young child who achieved favorable outcomes with timely corticosteroid therapy. CASE PRESENTATION: A 3-year-old girl presented with a 6-month history of recurrent fever, painful subcutaneous nodules, pruritic rashes, digital gangrene, myalgia, arthralgia, proteinuria, hematuria, and hypertension. Histopathologic examination of skin and subcutaneous nodules demonstrated necrotizing vasculitis of medium-sized arteries, fulfilling the EULAR/PRINTO/PRES classification criteria for cPAN. Treatment with oral prednisolone (1 mg/kg/day) and supportive care led to rapid improvement, including regression of skin lesions, normalization of inflammatory markers, resolution of renal involvement, and sustained remission during follow-up. CONCLUSION: This case highlights the need for high clinical suspicion of cPAN in children presenting with multisystem symptoms and characteristic cutaneous findings. Early diagnosis supported by established criteria and prompt corticosteroid therapy, combined with multidisciplinary care, can significantly improve outcomes and reduce long-term morbidity.