Rocky Mountain spotted fever is a bacterial infection passed to humans by wood ticks and dog ticks that can lead to life-threatening complications, such as shock and kidney failure, if it is not treated promptly. Initial symptoms usually start an average of 7 days after the tick bite and include a sudden fever, severe headache, muscle and joint aches, distinct rash, and nausea and vomiting.
The rash is usually made up of many tiny, flat, purple or red spots (petechial rash). It usually starts on the palms of the hands and soles of the feet, then spreads to the arms and legs and the rest of the body.
It is also called tick fever, spotted fever, or tick typhus. Rocky Mountain spotted fever is found in the southeastern, western, and south-central United States.