Rickettsialpox Eschar



40 homeless male from NY admitted with fever, chills, headache, myalgias. Diagnosis?

Rickettsialpox R akari classic triad of fever, vesiclar rash & eschar

Eschar is the hallmark. Primary papule➡️vesicle➡️eschar. Palpable draining tender lymph nodes are common. Rash appears 3-4d. Can have 20-40 lesions. Pts can recover w/o abx

Transmitted by bite of mouse mite so rickettsial pox linked to house mice. Another vector (tick or flea) is suspected & seen in dogs in NY. Target of R akari is macrophage (not endothelial cells as in other rickettsia)

Dx: serology; pcr from vesicle swabs; other infections vesicular rash: smallpox, chickenpox, vzv, hsv, Queensland tick typhus, African tick bite fever

Tx: rickettsial pox is doxycycline for 7d. Alternative chloramphenicol. susceptible to many other abx but efficacy unknown.



- Indiana University Infectious Diseases Fellowship @IUIDfellowship



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