To highlight a case of Ehrlichiosis with CNS manifestations and secondary hemophagocytic lymphohistiocytosis in a young immunocompetent patient to emphasize the importance of early disease recognition and treatment.

Ehrlichia chaffeensis is a bacterium that is transmitted by the Lone Star Tick and causes symptoms such as fever, headache, and malaise. In severe cases, CNS manifestations occur which are rare especially in immunocompetent patients. These manifestations range from meningoencephalitis, seizures, and coma. Systemic manifestations such as secondary hemophagocytic lymphohistiocytosis (HLH) and multi-organ failure can occur that require prompt treatment. A combination of secondary HLH and CNS manifestations of require prompt diagnosis and treatment for possible tick-borne illness. 

A 21-year-old female presented with fever, headache, and altered mental status. After admission, she had a witnessed 5-minute generalized tonic-clonic seizure. For a week prior to presentation, she had new onset cough and congestion. She was diagnosed with bronchitis, however symptoms continued, and she developed altered mental status. On admission, labs were significant for CSF studies showing elevated total nucleated cell count of 136 and elevated protein at 152. Serum studies showed anemia, thrombocytopenia, transaminitis, and acute kidney injury. There was evidence of elevated inflammatory markers, fibrinogen, and ferritin. Further testing revealed positive PCR for Ehrlichia chaffeensis. EEG monitoring showed bifrontal cortical and severe diffuse cerebral dysfunction.

The patient was started on Levetiracetam 750 mg twice daily for seizure prevention. Secondary HLH was treated with steroids and Ehrlichiosis was treated with doxycycline. The patient improved and was discharged after a prolonged ICU stay to acute rehab.