Bacillary angiomatosis

Background

• Caused by Bartonella henselae and Bartonella quintana
• Classically occurs in patients with advanced HIV

Clinical Manifestations

• Disseminated skin infection
• Characterized by protuberant, reddish-purple, berry-like nodules
  • Often surrounding dry scale
  • Can bleed profusely
  • More common on upper extremities
  • May arise in crops of papules and nodules
• Can affect essentially all internal organs as well
• Subcutaneous lesions are more common with Bartonella quintana
• Hepatic and splenic peliosis are more common with Bartonella henselae
  • Neovascular proliferation

Differential Diagnosis

• Essentially indistinguishable from Kaposi sarcoma in patients with HIV
• Pyogenic granuloma is the most notable differential diagnosis in immunocompetent hosts

Diagnosis

• Histopathology, culture, and PCR of skin lesions
• Notify lab, as may need prolonged incubation time

Management

• Treated by erythromycin 500 mg PO q6h or doxycycline 100 mg PO q12h for 3 or more months
  • Should start to respond within 3 to 4 weeks
  • Alternatives include fluoroquinolones or azithromycin
• Treatment of the underlying immunodeficiency, if applicable