Bacillary angiomatosis, which was first reported in 1983, is seen almost exclusively in HIV-positive patients with advanced disease. Cases have been extremely rare in recent years.

Bacillary angiomatosis is caused by the bacilli Bartonella henselae and B. quintana.

Bacillary angiomatosis is a systemic infection, and lesions have been described in nearly every organ of the body.

Untreated bacillary angiomatosis can be fatal.

Lesions may occur as erythematous dome-shaped papules and nodules (Fig. 33.11); they can also be flatter, violaceous lesions, subcutaneous nodules, or rarely, necrotic tumors.

There may be associated fever.

Bacillary angiomatosis can occur on any location of the skin or internally.

Untreated lesions can lead to respiratory obstruction, gastrointestinal bleeding, and local or systemic infection.

Deaths have been reported from laryngeal obstruction and disseminated intravascular coagulopathy.

Skin biopsy shows a lesion resembling pyogenic granuloma, with characteristic clusters of bacilli.

Culture is available only in research centers.