Rash is uncommon in anaplasmosis. Some patients infected with E. chaffeensisdevelop a maculopapular or petechial rash on the trunk and extremities.

RMSF vs. Ehrlichiosis

Rash RMSF: 90% patients, petechial in 50%

HME: rash 30% and maculopapular

HGE: rare

WBC Leukocytosis rare in either RMSF or

Ehrlichiosis

Leukopenia seen in Ehrlichiosis but rare

RMSF

Vasculitis Hallmark of RMSF; not seen Ehrlichiosis