Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Feb 22 2020

Bartonella henselae

  • Snapshot
    • A 26-year-old woman presents to the urgent care clinic because of fever, weight loss, night sweats, and a red rash on her trunk, legs, and arms for the past week. She has a past medical history of HIV infection and currently is not on any anti-retroviral medications. She recently adopted a cat from the shelter 3 months ago and has been training it to not scratch when approached; however, she has been sustaining scratches during the training process. On physical exam, she has generalized lymphadenopathy and multiple clusters of violaceous papules and plaques. Her CD4 count is 100 cells/mm3. A skin biopsy was done and shows a neutrophilic infiltrate and granulomatous changes.
  • Introduction
    • Classification
      • Bartonella henselae
        • facultative intracellular, gram-negative rod
        • transmission
          • scratch or bite from a cat (more common) or dog
        • clinical syndromes
          • bacillary angiomatosis, a vasoproliferative disease
            • benign capillary tumors of the skin
            • immunosuppressed patients
          • cat scratch disease
            • tender lymphadenopathy
          • bacterial endocarditis (culture-negative)
    • Epidemiology
      • incidence
        • more common in the southern US
      • demographics
        • bacillary angiomatosis
          • immunosuppressed patients
        • cat scratch disease
          • children and adolescents > adults
      • risk factors
        • HIV/AIDS
        • immunosuppression
        • cat scratch, bite, or lick
    • Pathogenesis
      • B. henselae replicates in red blood cells
      • granulomatous inflammation
        • mediated by CD4+ T-cells
        • secretes γ-interferon and activates macrophages
    • Associated conditions
      • culture-negative bacterial endocarditis
    • Prognosis
      • cat scratch disease typically resolves within a few months
      • bacillary angiomatosis typically resolves completely with treatment
  • Presentation
    • Cat scratch disease
      • tender lymphadenopathy 2 weeks after exposure
      • vesicle, wheal, or papule at site of trauma
      • systemic symptoms
        • low-grade fever
        • myalgias
        • fatigue
    • Bacillary angiomatosis
      • multiple clustered red or violaceous papules, plaques, or nodules on skin and mucosa
      • bone pain
      • systemic symptoms
        • fever
        • night sweats
        • weight loss
  • Studies
    • Labs
      • serologic detection of immunoglobulins
        • via enzyme-linked immunosorbent assay (ELISA) or indirect immunofluorescence assay (IFA)
      • detection of bacterial DNA on polymerase chain reaction (PCR)
      • culture is not useful as the bacteria is fastidious and hard to culture
    • Biopsy of skin lesions or lymph node
      • neutrophilic infiltrate
      • granulomatous changes
    • Making the diagnosis
      • based on clinical presentation and laboratory studies
  • Differential
    • Kaposi sarcoma
      • distinguishing factor
        • presents clinically similar to bacillary angiomatosis but biopsy reveals lymphocytic infiltrate
  • Treatment
    • Management approach
      • cat scratch disease is self-limited and guidelines for antibiotics is unclear
      • bacillary angiomatosis requires treatment with antibiotics
    • Medical
      • azithromycin
        • indication
          • cat scratch disease
      • erythromycin or doxycycline
        • indication
          • bacillary angiomatosis
  • Complications
    • Persistent lymphadenopathy
    • Aseptic meningitis
    • Disfigurement
1 of 0
1 of 3
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options