Tick-borne Relapsing Fever (TBRF)
- Average incubation time is 4-18 days.
- Two or more episodes of high fever typically greater than 102º F (39°C), headaches, and muscle soreness. The initial febrile episode lasts an average of 3 days with an average of 7 days between the initial episode and first relapse. On average patients with the tick-borne disease experience three relapses while those with the lice-borne disease experience only one. Patients tend to feel better between bouts; the febrile periods are characterized by a potentially lethal, although rare, period of unstable blood pressure.
- Chills, joint pain, nausea and vomiting, abdominal pain, mental status changes, nonproductive cough, diarrhea, dizziness, neck pain, photophobia, rash, and painful urination are possible.
- Louse-borne relapsing fever is treated with a single dose of 100 mg of Doxycycline by mouth.
- Tick-borne relapsing fever is treated with 100 mg of Doxycycline by mouth every 12 hours for 7-10 days. Doxycycline causes severe sun hypersensitivity; sun block is usually ineffective in preventing sunburn.
Spotted Fever Group Rickettsia (SFGR) Diseases
Initial symptoms of tick-borne SFGR infections are nonspecific and include fever, headache, fatigue, and muscle aches. A rash may be present; blackened or crusted skin (eschar) may develop at the site of a tick bite. Multiple eschars indicte multiple tick bites. The severity of illness may vary depending on the species.
- Doxycycline is the treatment of choice for patients of all ages. Adults: 100 mg every 12 hours; children under 45 kg (100 lbs): 2.2 mg/kg body weight given twice a day.
- Patients should be treated for at least 3 days after the fever subsides and until there is evidence of clinical improvement. Standard duration of treatment is 7 to 14 days.