Bacillary angiomatosis

[Magaret]

Bacillary angiomatosis is skin infection caused by the gram-negative bacteria Bartonella henselae or B. quintana.
(See also Overview of Bartonella Infections.)
Bacillary angiomatosis almost always occurs in immunocompromised people and is characterized by protuberant, reddish, berrylike lesions on the skin, often surrounded by a collar of scale. Lesions bleed profusely if traumatized. They may resemble Kaposi sarcoma or pyogenic granulomas.
Infection with B. quintana is spread by lice; infection with B. henselae is probably spread by fleas from household cats. Disease may spread throughout the reticuloendothelial system, causing bacillary peliosis (peliosis hepatis due to Bartonella bacteria), particularly in AIDS patients.
Diagnosis of bacillary angiomatosis relies on histopathology of the skin lesions, cultures, and polymerase chain reaction (PCR) analysis. The laboratory should be notified that Bartonella is suspected because special stains and prolonged incubation are necessary.
Treatment of bacillary angiomatosis is with oral erythromycin 500 mg every 6 hours or oral doxycycline 100 mg every 12 hours, continued for at least 3 months. Fluoroquinolones and azithromycin are alternatives.