Childhood polyarteritis nodosa presenting with central nervous system manifestations and the posterior reversible encephalopathy syndrome.

Polyarteritis nodosa is a systemic necrotizing vasculitis involving medium-sized muscular arteries. Polyneuropathy is the only neurologic manifestation included in the pediatric classification schema. Central nervous system manifestations include infarction, hemorrhage, and encephalitis. We report on a 13-year-old female whose initial presentation of polyarteritis nodosa included hypertension, seizures, and neuroimaging findings of vasogenic edema and posterior reversible encephalopathy syndrome. Posterior reversible encephalopathy syndrome has been reported in association with renal disease, transplantation, autoimmunity, and cytotoxic medications. Posterior reversible encephalopathy syndrome outcomes are usually favorable with supportive care and treatment of the underlying etiology. The patient's neurologic condition improved after treatment of hypertension. Hypertension, posterior reversible encephalopathy syndrome, and abdominal pain led to a diagnostic workup. A systemic vasculitis was confirmed after detection of a perinephric hematoma and intrarenal aneurysms. This is a novel case of posterior reversible encephalopathy syndrome as an initial manifestation of pediatric polyarteritis nodosa.