Rocky Mountain Spotted Fever (RMSF)

Three Rules to Follow

Rule # 1.  NEVER DELAY TREATMENT IF RMSF IS SUSPECTED.

Rocky Mountain spotted fever, Rickettsia rickettsii, (RMSF) is the most common rickettsial disease in the United States. It is a potentially fatal disease with a mortality rate as high as 30%.  Early treatment with appropriate antibiotics is required to prevent the disease progression and should be started as soon as the disease is suspected. 

The number of reported cases are increasing in the United States.  More than half of all reported cases are from North Carolina, Maryland, Virginia, Oklahoma, Tennessee, Arkansas and South Carolina.  Untreated cases may result in death within 20 days after exposure.  The hospitalization rate is over 70%, even in treated patients.  The incidence is highest amongst persons aged 5-9 years and in those who are 40-64 years old.

Symptoms can include:

  • High fever (>102°F), headaches, and myalgias (most common symptoms).
  • 25% of patients are reported to develop signs of encephalitis.
  • Confusion, lethargy, severe vertigo, ataxia, seizures, cranial nerve palsy, photophobia, dysarthria, paralysis and hearing loss may be noted. 
  • Gastrointestinal symptoms may include abdominal pain, diarrhea, nausea, and vomiting.  Splenomegaly and hepatomegaly may occur.
  • Some patients develop a maculopapular rash (mild to severe).  It often begins on the extremities (palms of hands and soles of feet) and spreads toward the trunk.  
  • Pulmonary edema, pneumonitis, shortness of breath may be present.
  • Petechial conjunctivitis, optic disc edema, anterior uveitis and retinal vascular dysfunction may occur. 
Rule # 2.  NEVER DELAY TREATMENT IF RMSF IS SUSPECTED.

Tests to detect RMSF may not indicate a person was exposed during the first several weeks of infection.  Never wait for tests results or depend on a negative test result if RMSF is suspected.  Treat immediately.  RMSF can be treated with antibiotics.  

Rule #3.  NEVER DELAY TREATMENT IF RMSF IS SUSPECTED. 

A course of oral doxycycline is usually recommended.  Severe disease may require long treatment courses and inadequately treated RMSF can cause multiple organ damage, chronic illness or death. 









































Subpages (1): New RMSF