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Doxycycline is appropriate for this life-threatening infection in pregnancy if suspicion is high, despite the potential risk to fetal bones/teeth.
Chloramphenicol may be considered during the first 2 trimesters but should be avoided in the 3rd trimester due to potential for gray baby syndrome.
ISSUES FOR REFERRAL
- Consider infectious disease consult.
- Report cases of RMSF to public health authorities.
ADDITIONAL THERAPIES
Patients with neurologic injury or loss of limbs caused by gangrene may require prolonged physical and cognitive therapy.
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
- CNS dysfunction
- Nausea/vomiting preventing oral antibiotic therapy
- Immunocompromised patients
- Specific acute organ failure
- Failure of oral pain management
- ICU placement for acutely ill patients with shock
IV Fluids
Aggressive fluid resuscitation and electrolyte management may be required in critically ill patients.
Discharge Criteria
- Resolution of fever
- Ability to take oral therapy and nutrition
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
- Hospitalize patients with moderate to severe disease
- Patients with mild disease may be treated as outpatients. Close follow-up is important to identify complications.
- Infection does not confer lifelong immunity.
Patient Monitoring
- Outpatients should be seen every 2 to 3 days until symptoms resolve.
- Follow up CBC, electrolytes, LFTs if clinically indicated.
DIET
Consider nutritional supplementation if intake is poor.
PROGNOSIS
- Prognosis is closely related to timely administration of appropriate antibiotics. Treatment before day 5 of illness can prevent morbidity and mortality (6).
- When treated promptly, prognosis is usually excellent with resolution of symptoms over several days and no sequelae.
- If complications develop, course may be more severe and long-term sequelae (especially neurologic sequelae) more likely (6).
- Children aged 5 to 9 years and elderly >70 years are at higher risk of morbidity and/or mortality (4,6).
- Black males with G6PD deficiency are at highest risk for fulminant RMSF, in which death can occur within 5 days (4).
COMPLICATIONS
- Encephalopathy (30 " 40%); most commonly transient impaired level of consciousness or meningismus
- Seizures, focal neurologic deficit (10%)
- Renal injury (10%)
- Hepatitis (10%)
- Congestive heart failure (CHF) (5%)
- Respiratory failure (5%)
- Proximal muscle weakness, changes in personality, paresthesias, distal necrosis, and deafness
REFERENCES
11 Lin L, Decker CF. Rocky Mountain spotted fever. Dis Mon. 2012;58(6):361 " 369.22 Pujalte GG, Chua JV. Tick-borne infections in the United States. Prim Care. 2013;40(3):619 " 635.33 Dahlgren FS, Holman RC, Paddock CD, et al. Fatal Rocky Mountain spotted fever in the United States, 1999 " 2007. Am J Trop Med Hyg. 2012;86(4):713 " 719.44 Woods CR. Rocky Mountain spotted fever in children. Pediatr Clin North Am. 2013;60(2):455 " 470. doi:10.1016/j.pcl.2012.12.001.55 Minniear TD, Buckingham SC. Managing Rocky Mountain spotted fever. Expert Rev Anti Infect Ther. 2009;7(9):1131 " 1137.66 Botelho-Nevers E, Raoult D. Host, pathogen and treatment-related prognostic factors in rickettsioses. Eur J Clin Microbiol Infect Dis. 2011;30(10):1139 " 1150.
CODES
ICD10
A77.0 Spotted fever due to Rickettsia rickettsii
ICD9
082.0 Spotted fevers
SNOMED
- 186772009 Rocky Mountain spotted fever (disorder)
- 240616003 Eastern Rocky Mountain spotted fever
- 240615004 Western Rocky Mountain spotted fever
CLINICAL PEARLS
- Diagnosis of RMSF requires a high index of clinical suspicion. Painless tick bites often go unnoticed, and some patients may never develop a rash.
- Treatment should begin immediately in suspected cases. Doxycycline is indicated for treatment of RMSF in both adults AND children. The only absolute contraindication is severe allergy to the drug.
- Lab testing is nonspecific and frequently normal.
- Although prevalence is highest in central and southeastern United States, cases have been reported in almost all states.