Bacillary angiomatosis

Bacillary angiomatosis was initially described as a condition occurring primarily in patients with AIDS and characterized by vascular cutaneous lesions resembling Kaposi's sarcoma. The disease can disseminate to involve virtually any organ system. Immunocompromised individuals, especially those infected with HIV, are at particularly high risk for bacillary angiomatosis, although in rare instances the patient is not obviously immunosuppressed. Both B. henselae and B. quintana (the infectious agent initially associated with trench fever) produce bacillary angiomatosis in persons with immunodeficiency.

Diagnosis of Bacillary angiomatosis

The diagnosis of bacillary angiomatosis is based primarily on the typical histopathologic findings of angiomas in association with clumps of tiny bacilli revealed by Warthin-Starry silver stain. Infection due to B. henselae can also be established by culture or by identification of specific DNA sequences. B. henselae is most easily isolated from blood through a lysis-centrifugation system.

The differential diagnosis of cutaneous bacillary angiomatosis includes Kaposi's sarcoma, angiomas, and pyogenic granulomas. These conditions can be distinguished by histopathologic examination of biopsied material.

Treatment of Bacillary angiomatosis

Patients with peliosis hepatis should be treated with intravenous antibiotics, and those with disseminated disease or bacteremia should be treated with a prolonged course (3 weeks to 2 months) of systemic antibiotic, such as a macrolide (e.g., erythromycin, 2 g/d). In a case-control study of bacillary angiomatosis, treatment with a macrolide was associated with a therapeutic response and sterile tissue samples and may have been protective, whereas treatment with trimethoprim-sulfamethoxazole, ciprofloxacin, penicillins, or cephalosporins had no protective effect. Cutaneous lesions may or may not regress spontaneously, perhaps depending on the status of the host's immunity.