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Disease overviewUnited States

What is Rocky Mountain spotted fever?

Rocky Mountain spotted fever is a potentially life-threatening bacterial illness spread by infected ticks. Fever and headache are common, and a rash may appear later or may be absent.

Reviewed by VuxLore® Knowledge Team For Everyone

Short answer

Rocky Mountain spotted fever is a potentially life-threatening bacterial illness spread by infected ticks. Fever and headache are common, and a rash may appear later or may be absent.

At a glance

Early medical recognition matters because treatment should not wait for a classic rash or delayed laboratory confirmation.

Key takeaways

• RMSF can progress rapidly.

• Its name does not limit it to the Rocky Mountains.

• Seek urgent medical care for compatible illness after tick exposure.

A serious rickettsial disease

RMSF is caused by Rickettsia rickettsii and is transmitted by several tick species in the United States. Early symptoms can be non-specific, including fever, headache, nausea and muscle pain.

Do not wait for spots

The rash often develops after fever has begun, and some patients never develop one. CDC advises clinicians to begin appropriate treatment when RMSF is suspected rather than waiting for test results.

Sources and further reading

US Centers for Disease Control and Prevention: About Rocky Mountain Spotted Fever

US Centers for Disease Control and Prevention: Tickborne Diseases of the United States