Abstract
Rocky Mountain spotted fever (RMSF) is a potentially lethal tick-borne disease caused by Rickettsia rickettsii, known for its tropism for vascular endothelial cells. Its classic symptoms include fever, headaches, and a rash, but atypical presentations can challenge diagnosis. We present the case of a 71-year-old male with fever, weakness, and hiccups, evolving into confusion. Laboratory findings showed severe hyponatremia, leukocytosis, and abnormal blood parameters. Initial management addressed sepsis and hyponatremia, leading to symptom improvement. Later, a fever of 106.5°F prompted ICU transfer, broad-spectrum antibiotics, and testing for tick-borne diseases. The patient reported tick exposure and received prophylactic doxycycline. Follow-up confirmed the RMSF diagnosis based on serological testing and clinical symptoms. This case highlights the diagnostic challenges posed by atypical RMSF presentations and underscores the importance of early detection and treatment to prevent complications.