The bacterial culprit in RMSF is called Rickettsia rickettsii. It causes no illness in the tick carrying it, and can be passed on to the tick's offspring.
Rocky Mountain spotted fever (RMSF) is a tick-borne illness caused by a bacteria, resulting in a high fever and a characteristic rash.
The bacteria causing RMSF is passed to humans through the bite of an infected tick. The illness begins within about two weeks of such a bite.
About 5% of all ticks carry the causative bacteria. Children under the age of 15 years have the majority of RMSF infections.
The rash of RMSF is quite characteristic. It usually begins on the fourth day of the illness, and occurs in at least 90% of all patients with RMSF. It starts around the wrists and ankles, as flat pink marks (called macules).
Prior to the regular use of antibiotics to treat RMSF, the death rate was about 25%. Although the death rate from RMSF has improved greatly with an understanding of the importance of early use of antibiotics, there is still a 5% death rate.
It is essential to begin treatment absolutely as soon as RMSF is seriously suspected. Delaying treatment can result in death.
Certain risk factors suggest a worse outcome in RMSF. Death rates are higher in males and increase as people age. It is considered a bad prognostic sign to develop symptoms of RMSF within only two to five days of a tick bite.
It is appropriate to shorten Rocky Mountain spotted fever to simply RMSF. It is a term used by the Centers for Disease Control (CDC).
Antibiotics given by the doctor as soon as they suspect RMSF. Waiting for laboratory confirmation can put the patient at greater risk, due to the fast progress of the prokaryotic bacteria.
Rickettsia rickettsii is the scientific name for RMSF. The common name for it is Rocky Mountain Spotted Fever.
Unlike rashes which accompany various viral infections, the rash of RMSF does spread to the palms of the hands and the soles of the feet. Over a couple of days, the macules turn a reddish purple color.
Diagnosis of RMSF is almost always made on the basis of the characteristic symptoms, coupled with either a known tick bite (noted by about 60-70% of patients) or exposure to an area known to harbor ticks.