Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever (RMSF) is an infection caused by the bite of an infected tick. In recent years, it has affected over 2,000 people a year in the U.S. and usually occurs from April until September, but it can occur anytime during the year where weather is warm. The mid-Atlantic and southeastern states are most affected. The disease is spread to humans through a bite from an infected tick; it is not spread from one person to another.

In the U.S., the American dog tick (Dermacentor variabilis), the Rocky Mountain wood tick (Dermacentor andersoni), and the brown dog tick (Rhipicephalus sanguineus), have been identified as vectors that transmit the RMSF bacteria.

What are the symptoms of Rocky Mountain Spotted Fever?

The following are the most common symptoms of RMSF. However, each person may experience symptoms differently. Symptoms may include:

RMSF is a serious illness that needs treatment as soon as possible. Death has occurred in untreated cases of RMSF.

Symptoms of RMSF may resemble other conditions or medical problems. Consult a doctor for diagnosis.

How is RMSF diagnosed?

Diagnosis is based on symptoms and past history of a tick bite. The appearance and character of the rash is important. Skin samples and lab tests (antibody titer, kidney function tests, platelet count, prothrombin time, partial thromboplastin time, urinalysis, and red blood cell count) are usually done to rule out other conditions and confirm diagnosis.

What is the treatment for Rocky Mountain Spotted Fever?

Specific treatment for RMSF will be determined by your doctor and may include antibiotics (usually doxycyline until several days after the fever goes away) and supportive care.

How can Rocky Mountain Spotted Fever be prevented?

Once a person has RMSF, he/she cannot be reinfected. Some general guidelines for preventing RMSF include:

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