Rickettsial Meningoencephalitis With Multiorgan Failure in a Previously Healthy Young Adult.

Rickettsioses are zoonotic infections caused by obligate intracellular gram-negative bacteria of the genus Rickettsia. Although they commonly present as an acute febrile illness with rash, central nervous system involvement is uncommon and may be associated with severe morbidity and mortality. A previously healthy 28-year-old man presented with fever and acute gastrointestinal symptoms followed by the development of a centrifugal macular rash involving the trunk, extremities, palms, and soles. He subsequently developed progressive somnolence and language disturbances, progressing to severe neurological impairment requiring mechanical ventilation. Laboratory studies revealed thrombocytopenia, acute kidney injury, hyponatremia, and hepatic dysfunction. Brain computed tomography (CT) demonstrated subtle loss of gray-white matter differentiation and mild sulcal effacement, findings suggestive of diffuse cerebral edema. Cerebrospinal fluid analysis, blood cultures, and multiplex polymerase chain reaction (PCR) testing for common bacterial, viral, and fungal pathogens were unrevealing. Further examination identified an inoculation eschar on the left lower extremity. Conventional serum PCR testing was positive for Rickettsia spp., supporting the diagnosis of rickettsial meningoencephalitis, although species-level identification was not available. Intravenous doxycycline was initiated in addition to empiric antimicrobial therapy; however, the patient developed progressive multiorgan failure and failed to demonstrate meaningful neurological recovery. This case highlights the importance of considering rickettsiosis in the differential diagnosis of meningoencephalitis in endemic regions, particularly when fever, rash, and neurological manifestations coexist. Early recognition and prompt initiation of doxycycline remain essential to reduce the risk of severe neurological complications and poor clinical outcomes.