Rickettsial Diseases - Infectious Dis.

Snapshot
- A 30-year-old woman presents to the emergency room for a rash. She had been traveling and hiking in southern Europe. She does not recall having any tick bites but admits that it may be possible as she had many bug bites on her legs, though she attributed these to mosquitoes. She started having fevers 2 days ago along with a severe headache and developed a rash today. On physical exam, she has a maculopapular rash on her trunk as well as multiple eschars surrounding a bug bite on her left calf. She is started on doxycycline. (Mediterranean spotted fever)

Presentation

Rickettsial Diseases
Clinical Manifestations of Rickettsial Diseases
Disease	Vector	Rash	Eschar	Regional Lymphadenopathy
Rocky Mountain spotted fever (R. rickettsii)	Tick	Macular Petechial Purpuric Spreads centripetally (extremities to trunk)	No	No
Mediterranean spotted fever (R. conorii)	Tick	Macular Papular Purpuric	Yes	No
Rickettsialpox (R. akari)	Mite	Vascular Papular On trunk and extremities	Yes	Yes
African tick bite fever (R. africae)	Tick	Vesicular Maculopapular	Yes, multiple	Yes
Epidemic tyhpus (R. prowazekii)	Louse	Macular Papular Petechial Spreads centrifugally (trunk to extremities)	No	No
Murine typhus (R. typhi)	Flea	Macular Papular Petechial Spreads centrifugally	No	No
Scrub typhus (O. tsutsugamushi)	Mite	Macular Pale	Yes	Yes

Prognosis
- Most resolve with treatment
- Epidemic typhus (R. prowazekii) may recur (Brill-Zinsser disease)
- Rocky Mountain spotted fever (R. rickettsii) has the highest mortality

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