Rocky Mountain spotted fever physical examination

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

There are several aspects of Rocky Mountain spotted fever (RMSF) that make it challenging for healthcare providers to diagnose and treat. The symptoms of RMSF vary from patient to patient and can easily resemble other, more common diseases. Treatment for this disease is most effective at preventing death if started in the first five days of symptoms. Diagnostic tests for this disease, especially tests based on the detection of antibodies, will frequently appear negative in the first 7-10 days of illness. Due to the complexities of this disease and the limitations of currently available diagnostic tests, there is no test available at this time that can provide a conclusive result in time to make important decisions about treatment.For this reason healthcare providers must use their judgment to treat patients based on clinical suspicion alone. Healthcare providers may find important information in the patient’s history and physical examination that may aid clinical suspicion. Information such as recent tick bites, exposure to high grass and tick-infested areas, contact with dogs, similar illnesses in family members or pets, or history of recent travel to areas of high incidence can be helpful in making the diagnosis.

The diagnosis of RMSF must be made based on clinical signs and symptoms, and can later be confirmed using specialized confirmatory laboratory tests. Treatment should never be delayed pending the receipt of laboratory test results, or be withheld on the basis of an initial negative finding for R. rickettsii.

Initial physical signs may include:

• Fever
• Muscular tenderness
• Anorexia ^[1]

Later signs and symptoms include:

• Maculopapular rash
• Petechial rash
• Abdominal tenderness
• Joint pain ^[1]

• Patients with RMSF (90%) have some type of rash during the course of illness
• Rash may not appear until after early onset symptoms, however treatment should start upon suspicion.
• A classic case of RMSF involves a rash that first appears 2-5 days after the onset of fever
• Rash appears as small, flat, pink, non-itchy spots (macules) on the wrists, forearms, and ankles and spreads to include the trunk and sometimes the palms and soles.
• Often the rash varies from this description and people who fail to develop a rash, or develop an atypical rash, are at increased risk of being misdiagnosed.
• The red to purple, spotted (petechial) rash of RMSF is usually not seen until the sixth day or later after onset of symptoms and occurs in 35-60% of patients with the infection.
• A transition of red to purple coloration indicates a progression to severe disease, and every attempt should be made to begin treatment before petechiae develop.
• It is important for physicians to consider RMSF if other signs and symptoms support a diagnosis, even if a rash is not present.

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  Early stage rash in a patient with RMSF
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  Early stage rash in a patient with RMSF
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  Later stage rash in a patient with RMSF
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  Rocky Mountain spotted fever is a potentially fatal infection transmitted to humans by ticks. This photograph shows the classical appearing rash which often begins on the wrists and ankles, and spreads rapidly towards the center of the body. The rash may also be present on the palms and soles
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  Rocky Mountain Spotted Fever is a disease transmitted to humans by a tick bite. The spots begin as flat (macular) red (erythematous) patches that may bleed into the skin, causing purplish spots (purpura). The disease is named after its characteristic spots.
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  Rocky Mountain spotted fever is caused by the organism Rickettsia rickettsii and is transmitted by a tick bite. It is a serious infection that produces a classical rash in about 90% of infected individuals. This is the typical appearance of the rash. There are many symptoms that affect the entire body (systemic)