Bacillary angiomatosis: a role for Phyllobacterium?

The role of Bartonella sp. in the aetiology of bacillary angiomatosis has been firmly established. This report, however, describes a case of bacillary angiomatosis with unusual clinical features, and presents evidence for the involvement of organisms closely related to Phyllobacterium sp., a genus of bacteria previously only associated with leaf nodule disease in tropical higher plants. A 40-year-old HIV-seropositive homosexual man (CD4+ lymphocyte count 20 x 10 super(6)/l) presented with a 1-week history of dysentery associated with tenesmus, nausea, anorexia, malaise and intermittent abdominal pain. On admission he was pyrexial with marked tenderness in the posterior anal canal. Plain abdominal radiography demonstrated dilated loops of large bowel, with thickened walls in the region of the sigmoid colon. No pathogens were detected in stool or peripheral blood despite repeated sampling. Examination under general anaesthetic showed severe inflammation of the entire anal and rectal mucosa, with much blood and mucus. Histological examination of rectal biopsy specimens revealed a clear diagnosis of bacillary angiomatosis, confirmed by the identification of aggregates of bacilli in fibrinoid material within the lamina propria on Warthin-Starry staining.