Bacillary angiomatosis is skin infection caused by 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 PCR analysis. The laboratory should be notified that Bartonella is suspected because special stains and prolonged culture growth are necessary.
Treatment of bacillary angiomatosis is with erythromycin 500 mg po q 6 h or doxycycline 100 mg po q 12 h, continued for at least 3 mo. Fluoroquinolones and azithromycin are alternatives.