Fever rocky mountain spotted

Skin | General Practice | Fever rocky mountain spotted (Disease)


Rocky Mountain spotted fever remains a serious and potentially life-threatening infectious disease today. Despite the availability of effective treatment and advances in medical care, approximately three to five percent of patients who become ill with Rocky Mountain spotted fever die from the infection.

However, effective antibiotic therapy has dramatically reduced the number of deaths caused by Rocky Mountain spotted fever. Before the discovery of tetracycline and chloramphenicol during the latter 1940s, as many as 30 percent of persons infected with R. rickettsii died.

The most common symptoms of Rocky Mountain spotted fever include a red rash, fever, and joint pain. The rash begins on the wrist and ankles, and then spreads to the trunk. Additional symptoms may include headache, muscle aches, nausea, vomiting, diarrhea, abdominal pain, and fatigue. Symptoms of severe Rocky Mountain spotted fever include high fever, worsening headache, neck pain and stiffness, excessive sleepiness, confusion, and seizures.

Causes and Risk factors

Rocky Mountain spotted fever (RMSF) is a tick-borne disease caused by the organism Rickettsia rickettsii. Although RMSF can be lethal, it is curable. RMSF is the most common rickettsial infection. The organism is endemic in parts of North, Central, and South America, especially in the southeastern and south-central United States.

Cases of RMSF occur when the appropriate tick vector comes in contact with human populations. Risk factors include traveling to an area with a high rate of RMSF, especially in seasons when ticks are plentiful, such as summer. People at highest risk are those who frequent forested areas or fields, such as those who are hiking or camping. Even urban outdoor areas pose a risk, however. Dog ownership is a risk factor in areas where the American dog tick exists. Dogs acquire ticks while roaming outside, and these ticks can be transferred to humans during petting or other contact.

Diagnosis and Treatment

The disease is diagnosed by finding high titers of antibodies in the blood or by seeing the organism under a microscope in specially stained skin biopsies.

The treatment of choice is the antibiotic doxycycline (Vibramycin, Oracea, Adoxa, Atridox). Prompt treatment improves survival and reduces complications. ...