Dengue hemorrhagic fever presenting as encephalitis: a case report

BACKGROUND: Dengue fever and dengue hemorrhagic fever incidence is increasing in Sri Lanka, especially among the young population. Uncommon presentations of this common illness make diagnostic dilemmas and can delay standard treatment which leads to unfavorable outcomes. CASE PRESENTATION: An 18-year-old Sri Lankan Sinhalese boy presented with a history of 1 day of fever and an episode of seizure followed by left-side hemiparesis. He was diagnosed to have dengue complicated by dengue hemorrhagic fever and recovered with minimal residual weakness. He presented with neurological symptoms; cerebrospinal fluid analysis, electroencephalogram, and magnetic resonance imaging showed evidence of encephalitis. Positive dengue antigen and antibody in serum and cerebrospinal fluid with the exclusion of other possible etiologies confirmed parainfectious dengue encephalitis. He was started on sodium valproate 200 mg 8 hourly and made a slow neurological recovery with mild residual weakness (grade 4+ power) in his left upper limb at 2 months with intensive supervised physiotherapy. CONCLUSION: Standard national guideline-based management of dengue illness has significantly reduced its mortality rates in Sri Lanka. However, uncommon presentations of a common illness often cause diagnostic dilemmas. Hence, reporting of these presentations and knowing the epidemiologic patterns of the disease help physicians to arrive at the correct diagnosis even though they do not have sophisticated serological investigations. Overall, this can improve the quality of health care and reduce mortalities, especially in a resource-poor setup.