Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Rocky Mountain spotted fever (RMSF) is a bacterial disease spread through the bite of an infected tick. Most people who get sick with RMSF will have a fever, headache, and rash. RMSF can be deadly if not treated early with the right antibiotic.

Rocky Mountain spotted fever is one of several diseases caused by the spotted fever group rickettsia, which are a type of bacteria. Other causes of spotted fever group rickettsioses (spotted fevers) in the United States include:

  • Rickettsia parkeri rickettsiosis, caused by R. parkeri
  • Pacific Coast tick fever, caused by Rickettsia philipii
  • Rickettsialpox, caused by Rickettsia akari

These diseases have similar signs and symptoms, including fever, headache, and rash, but are often less severe than RMSF.

Related Tick Topics

Avoiding Ticks

Avoid getting infected…On CDC’s Ticks website

Tick Lifecycle and Hosts

How ticks spread disease…On CDC’s Ticks website

Removing a Tick

How to remove a tick…On CDC’s Ticks website

Other Diseases Caused by Ticks

Learn more about other tickborne diseases that can affect your health…On CDC’s Ticks website

TOP