DR Medhat MRCP

IV. Ricketsiae
A. African Tick Typhus :
• Diagnosis :
Balck sopits on thigh.
H/O tick bite.
Low grade fever
Faint macular rash.
B. Rocky mountain spotted fever :
- It`s the most lethal & most frequently reported rickettsial infection
- Spread by ticks
- Common in USA.
• Presentation :
Fever.
Rash on the hands ,feet which later desquamate.
Tachycardia without hypotesion (unlike staph TSS).
C. Mediterranean Spotted Fever (Boutonneuse fever):
- It`s is a fever caused by the Rickettsia conorii and transmitted by the dog tick
Rhipicephalus sanguineus.
- Incubation period: 7 days.
• Features : abrupt onset of
1) Chills
2) High fevers, myalgia and joints pain,
3) Severe headache, photophobia and diarrhea.
4) The location of the bite forms a black spots or ulcerous crust (tache noire).
5) Around the fourth day of the illness an exanthem (widespread rash) appears, first
macular and then maculopapular and sometimes petechial.
• Treatment : Doxycycline.
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