Bacillary Angiomatosis

(See also Overview of Bartonella Infections Overview of Bartonella Infections Bartonella species are gram-negative bacteria previously classified as Rickettsiae. They are facultative intracellular organisms that typically live within red blood cells (RBCs) and... read more .)

Bacillary angiomatosis almost always occurs in immunocompromised people and is characterized by protuberant, purple to bright red, berrylike lesions on the skin, often surrounded by a collar of scale. Lesions bleed profusely if traumatized. They may resemble Kaposi sarcoma Kaposi Sarcoma Kaposi sarcoma is a multicentric vascular tumor caused by herpesvirus type 8. It can occur in classic, AIDS-associated, endemic (in Africa), and iatrogenic (eg, after organ transplantation)... read more or pyogenic granulomas Pyogenic Granulomas Pyogenic granulomas are fleshy, moist or crusty, usually scarlet vascular nodules composed of proliferating capillaries in an edematous stroma. The lesion, composed of vascular tissue, is neither... read more .

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 Peliosis Hepatis Peliosis hepatis is typically an asymptomatic disorder in which multiple blood-filled cystic spaces develop randomly in the liver. (See also Overview of Vascular Disorders of the Liver.) Measuring... read more 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.