Rocky Mountain spotted fever (RMSF) is a bacterial disease spread through the bite of an infected tick.
Early signs and symptoms are not specific to RMSF (including fever and headache). However, the disease can rapidly progress to a serious and life-threatening illness.
Signs and symptoms can include:
If you become ill after having been bitten by a tick, having been in the woods, or in areas with high brush where ticks commonly live, see your healthcare provider.
A rash is a common sign of RMSF. It usually develops 2 to 4 days after fever begins. The look of the rash can vary widely over the course of illness. Some rashes can look like red splotches and some look like pinpoint dots. RMSF is challenging to diagnose since the rash, a common symptom, often appears late in the illness.
RMSF does not result in chronic or persistent infections. Some patients who recover from severe RMSF may be left with permanent damage, such as:
Any permanent damage is caused by the acute illness and does not result from a chronic infection.
Rocky Mountain spotted fever is a serious tickborne illness which can be deadly if not treated early. It is spread by several species of ticks in the United States, including:
RMSF cases occur throughout the United States.
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There is no vaccine to prevent RMSF. Prevent illness by preventing tick bites on yourself, on your pets, and in your yard.
Tick exposure can occur year-round, but ticks are most active during warmer months (April-September). Know which ticks are most common in your area.
Your healthcare provider may order certain blood tests to look for evidence of RMSF. The results of these tests can take weeks. If your healthcare provider thinks your illness might be RMSF, they should recommend antibiotic treatment before test results are available.
RMSF can be life-threatening. Early treatment with the antibiotic doxycycline can prevent death and severe illness. It is approved for adults and children of all ages.
