Bacillary Angiomatosis

Description

Depicted on an adult male in anatomical position, multiple discrete bright red, shiny papules are scattered over the anterior thoracic and abdominal skin and extend onto the proximal upper limbs. Lesions sit superficially within the integument, clustered across the chest wall and upper abdomen with relative sparing of the face, hands, and lower limbs in this presentation. The neutral stance with arms adducted and palms facing anteriorly keeps the distribution pattern readable across the torso and medial brachium. Bacillary angiomatosis represents a Bartonella infection (classically Bartonella henselae or Bartonella quintana) producing lobular capillary proliferation with plump, epithelioid-appearing endothelial cells and a neutrophil-rich inflammatory background, often in the setting of advanced HIV/AIDS. Clinically, these vascular lesions can mimic Kaposi sarcoma, cherry angiomas, or pyogenic granuloma, and the distinction matters because bacillary angiomatosis is treatable with macrolides or doxycycline while Kaposi sarcoma prompts evaluation for HHV-8 disease burden and immune status. Biopsy with Warthin-Starry or silver staining, plus Bartonella PCR when available, supports diagnosis. Pattern recognition helps. Use this asset in dermatology and infectious disease teaching blocks to illustrate cutaneous distribution, lesion morphology, and the classic association with immunosuppression, and in HIV medicine publications discussing opportunistic infections with vascular skin findings. It also fits patient-education materials that explain why new angiomatous papules warrant prompt evaluation rather than watchful waiting. Anatomical accuracy verified by SciePro's Medical Advisory Board.