What Is Rocky Mountain Spotted Fever?
Rocky Mountain spotted fever (RMSF) is a serious bacterial infection spread through the bite of an infected tick. The infection is caused by bacteria carried by certain ticks, including the American dog tick and Rocky Mountain wood tick. People who spend time outdoors in wooded or grassy areas may have a higher risk of exposure.
Although it was first identified in the Rocky Mountain region, RMSF can occur in many areas of the United States, especially during warmer months when ticks are more active. The illness can affect multiple parts of the body and may become severe if treatment is delayed.
Symptoms
Symptoms of RMSF often begin within several days after a tick bite. Early treatment is important because the infection can worsen quickly.
Common symptoms may include:
- Fever
- Headache
- Rash
- Chills
- Muscle aches
- Nausea or vomiting
- Diarrhea
- Stomach pain
- Fatigue
- Sensitivity to light
- Confusion in severe cases
How Is It Diagnosed?
Healthcare providers diagnose RMSF by reviewing symptoms, recent outdoor activity, and possible tick exposure. A physical exam and evaluation of the rash can also help guide diagnosis.
Testing may include:
- Blood tests
- Skin or tissue samples
- Laboratory testing for tick-borne infections
Because RMSF can become serious quickly, treatment may begin before test results are confirmed.
How Is It Treated?
RMSF is treated with antibiotics, most commonly doxycycline. Early treatment greatly lowers the risk of serious complications.
Treatment may also include:
- Fluids and supportive care
- Fever and pain management
- Monitoring for complications
Most people recover well when treated promptly. Without treatment, RMSF can lead to severe complications affecting the nervous system, kidneys, blood vessels, or other organs.
