Rocky Mountain Spotted Fever

Also known as: RMSF.

What is Rocky Mountain spotted fever?

Rocky Mountain spotted fever is an illness that that can be transmitted from a tick bite. Though the illness was first discovered in the Rockies, it can actually occur in a number of different locations.

What causes Rocky Mountain spotted fever?

A bacteria known as Rickettsia rickettsii causes Rocky Mountain spotted fever. The disease is usually transmitted to humans if a tick with the bacteria feeds on a person for 6 to 10 hours or more.

What are the symptoms of Rocky Mountain spotted fever?

Symptoms of Rocky Mountain spotted fever include chills, headache, muscle aches, nausea and vomiting, high fever and restlessness. A few days later, a red rash occurs that spreads around the body.

What are Rocky Mountain spotted fever care options?

Rocky Mountain spotted fever responds well to antibiotic treatments. People should begin these treatments early to ensure the best results.

Reviewed by: Carolina Sanchez-Vegas, MD

This page was last updated on: September 16, 2025 12:28 PM