Common Tick-borne Illnesses

Amanda Bogie, MD

Rocky Mountain Spotted Fever (RMSF)

  • Caused by infection with bacterium Rickettsia rickettsii from the tick bite
  • Symptoms include the following: Fever, headache, myalgia, conjunctivitis vomiting, seizures, myocarditis, heart failure, shock, periorbital /facial edema, toxic appearing rash on the ankles and wrists (petechial then truncal), disseminated intravascular coagulation (DIC), purpura fulminans, thrombocytopenia, hyponatremia, elevated aminotransferases.

Image Courtesy of Ohio Department of Health (http//

  • Treat early after clinical diagnosis with Doxycycline.

Lyme disease

  •  Most common vector borne illness in the US
  • Caused by the Borrelia burgdoferi from tick genus Ixodes
  • Disease of 3 stages
      • First stage- Flulike illness, tender lymphadenopathy, erythema migrans – circular expanding rash with target-like appearance
    • F
    • Figure: Erythema migrans rash: “Classic” lyme disease rash with circular expanding rash with targetlike appearance
      • Next stage- Carditis (heart block), cranial nerve VII/Bell’s palsy
      • Late stage- Arthritis, large joints (knees)
    • Treat with Amoxicillin if <8 years, then doxycycline. If ill,  IV Ceftriaxone, as needed.


  • Obligate intracellular bacteria with three types.
      • Ehrlichia chaffeensis or Human Monocytic Ehrlichiosis (HME)
      •  Anaplasma phagocytophilum or Human Granulocytic Anaplsmodsis (HGA)
      •  Ehrlichia ewingii
    • Predominately found in the southcentral and eastern United States
    • Causes febrile illness with headache and rash with many forms
    • Leukopenia, anemia, hepatitis more common
    • Treat early after clinical diagnosis with Doxycycline


  • Spreads from infected dog ticks, lone star ticks, wood ticks or infected rabbits, hamsters, or deerfly bites
  • Caused by Francisella tularensis
  • Found in South Central US
  • Symptoms include the following: Fever and tender cervical and occipital Lymphadenopathy
  • Treat with Doxycycline

STARI (Southern tick-associated rash illness)

  • Spread from Lone Star tick bite
  • Found mainly in Southeast and eastern United States
  • Symptoms include the following: Fever, headache, rash, arthralgia
  • Treat with Doxycycline

Colorado Tick Fever

  • Rocky mountain wood tick-virus
  • Found in Western US and Western Canada
  • Flu like illness caused by a virus
  • No treatment

Tickborne Relapsing Fever (TBRF)

  • Spread by infected soft ticks
  • Occurs in 15 states, including Oklahoma
  • Risk factor: Sleeping in rustic cabins
  • Flu-like illness
  • No Treatment


  • Microscopic parasites that infect red blood cells
  • Found mainly in the Northeast and Midwest
  • Flu-like illness
  • Treat with combination of 2 medications, either clindamycin and quinine, or atovaquone and azithromycin.



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