Idiopathic Hypereosinophilic Syndrome Presenting With Meningoencephalitis; an Uncommon Presentation: A Case Report

Abstract

Introduction: Hypereosinophilic syndrome is a rare heterogeneous disorder characterized by persistent eosinophilia with eosinophil mediated tissue infiltration and organ dysfunction in the absence of a secondary cause. Clinical presentations involving nervous system vary markedly causing encephalopathy, thromboembolic disease or peripheral neuropathy. Eosinophilic infiltration of meninges and central nervous system causing meningo-encephalitis is a rare presentation in hypereosinophilic syndrome and is infrequently published in scientific literature. Case presentation: A previously healthy 19-year-old Sri Lankan male presented with mild fever, headache and photophobia with abnormal behavior. On examination, he was drowsy with neck stiffness, positive Kernig’s sign, hypertonia and quadri-hyperreflexia. Cerebrospinal fluid analysis revealed heavy eosinophilic infiltration with sterile cultures. Peripheral blood smear showed persistent absolute eosinophilia and bone marrow revealed hyper-cellularity with eosinophil predominance. Other organ involvement was also noted with global hypokinesia of myocardium on echocardiogram and moderate restrictive lung disease. Secondary causes for hypereosinophilia were excluded and he made a remarkable recovery following treatment with steroids for idiopathic hypereosinophilic syndrome. Conclusion: Although rare, eosinophilic infiltration of cerebrospinal fluid (with sterile cultures) and peripheral blood absolute eosinophilia should prompt the physician towards the diagnosis of idiopathic hypereosinophilic syndrome in the absence of secondary causes, as early treatment can be lifesaving.