Abstract:
Background: Bacillary angiomatosis (BA) is a rare manifestation of infection caused by Bartonella species, which leads to
vasoproliferative lesions of skin and other organs. Bacillary angiomatosis affects individuals with advanced HIV disease or
other immunocompromised individuals. In sub-Saharan Africa, despite the high prevalence of HIV infection and documentation
of the causative Bartonella species in humans, mammalian hosts, and arthropod vectors, BA has only rarely been described.
Methods: Three adult patients from Uganda and Kenya with deep purple dome-shaped papules or nodules of the skin underwent
punch biopsies for histopathologic diagnosis. The biopsies of all 3 patients were sent to a local pathologist as well as to a derma-
topathologist at the University of California, San Francisco. Results: All 3 patients were clinically suspected to have Kaposi’s
sarcoma (KS), and local pathologists had interpreted the lesions as KS in 2 of the cases and nonspecific inflammation in the
third. Histologic examination by dermatopathologists in the United States revealed nodular dermal proliferations of irregular
capillaries lined by spindled to epithelioid endothelial cells. The surrounding stroma contained a mixed inflammatory infiltrate
with lymphocytes, eosinophils, and neutrophils. Extracellular deposits of pale amphophilic granular material were noted in the
surrounding stroma. A Warthin-Starry stain highlighted clumps of bacilli, confirming the diagnosis of BA. Conclusions: These 3
cases, to our knowledge, are the first reports of BA in East Africa in the biomedical literature. Each had been originally
incorrectly diagnosed as KS. We speculate BA is underdiagnosed and underreported in resource-poor regions, such as sub-
Saharan Africa, that have high endemic rates of HIV infection.
