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Abstract

Introduction: Background: Henoch-Schonlein purpura (HSP) is a common pediatric disease that presents secondary to immune-complex mediated vasculitis, with subsequent sequelae of nephrotic insult and resulting hypertension (HTN). We report a rare case of HSP with malignant hypertension without the typical renal involvement resulting in posterior reversible encephalopathy syndrome (PRES). Methods: 8-year-old male with recently diagnosed HSP presented with obtundation and status epilepticus secondary to HTN, with presenting blood pressure of 170/115, despite normal renal function and no proteinuria. MRI revealed multifocal bilateral increased signal within the brain parenchyma. Continuous labetalol was given to control hypertension with resolution of symptomatology after achieving BP control. Repeat MRI after resolution of symptoms demonstrated improvement of hyper-dense signals on MRI, consistent with the diagnosis of PRES. Results: There are two mechanisms by which HSP may be linked to PRES in the absence of nephrotic syndrome. An acute rise in blood pressure may outpace the sympathetic autoregulation of blood vessels, causing simultaneous and opposing vasodilation and vasoconstriction that result in reversible cerebral edema. Alternatively, the vasculitis incited by HSP may cause breakdown in the blood-brain barrier with ensuing cerebral edema. As in our case, treatment of the hypertension and HSP resulted in resolution of the cerebral edema, determining the diagnosis of PRES. Conclusions: Our patient represents a pediatric case of HSP with PRES secondary to malignant hypertension without renal involvement that has been infrequently reported in the medical literature. Given the prevalence of HSP in the pediatric population, pediatric critical care clinicians should be aware that PRES may develop in patients with HSP subsequent to acute rise in blood pressure as well as vasculitis and reversible cerebral edema.