Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 32-12: Spotted Fevers + Key Features Download Section PDF Listen +++ ++ An acute, self-limiting, febrile illness Caused by Rickettsia akari, a parasite of mice, transmitted by the mite Liponyssoides sanguineus Infections are reported globally Crowded conditions and mouse-infested housing allow transmission of the pathogen to humans Has also been found in farming communities + Clinical Findings Download Section PDF Listen +++ ++ Primary lesion is a painless red papule that vesiculates and forms a black eschar followed by an incubation period of 7–12 days Onset of symptoms is sudden, with chills, fever, headache, photophobia, and disseminated aches and pains Widespread papular eruption appears 2–4 days later Rash becomes vesicular and forms crusts that are shed in about 10 days Early lesions may resemble those of chickenpox (typically vesicular versus papulovesicular in rickettsialpox) Pathologic findings include dermal edema, subepidermal vesicles, and a lymphocytic vasculitis + Diagnosis Download Section PDF Listen +++ ++ Transient leukopenia and thrombocytopenia and acute hepatitis can occur A fourfold rise in serum antibody titers to rickettsial antigen, detected by complement fixation or indirect fluorescent assays Conjugated antirickettsial globulin can identify antigen in punch biopsies of skin lesions Polymerase chain reaction (PCR) detection of rickettsial DNA in fresh tissue R akari can also be isolated from eschar biopsy specimens + Treatment Download Section PDF Listen +++ ++ Oral doxycycline (100 mg twice daily) for 2–5 days until defervescence Severe symptoms may require hospitalization Control requires the elimination of mice from human habitations and insecticide applications