A 42-year-old male hiker returns from a camping trip in North Carolina and presents with fever, severe headache, and muscle aches. He reports that he removed a tick from his leg about 5 days ago. On examination, you note a maculopapular rash on his wrists and ankles, which has started spreading centrally. He also complains of nausea and abdominal pain. Which of the following clinical features is most characteristic of Rocky Mountain Spotted Fever (RMSF)?
