Updated: 2/22/2020

Bartonella henselae

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
3 3
0
0
0%
0%
Evidence
2 2
0
0
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
 

Please rate topic.

Average 4.7 of 6 Ratings

Questions (3)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.MC.14.1) A 16-year-old female presents to her pediatrician complaining of 2 weeks of fever and 1 week of swollen lumps in her left armpit. Upon examination of the left upper extremity, her physician notes the presence of a single papule which the patient claimed appeared one week ago. The patient started her first job at a pet store 2.5 weeks ago. Which of the following is the vector of transmission of the causative agent? Tested Concept

QID: 106429
FIGURES:
1

Animal urine

3%

(2/63)

2

Cats

81%

(51/63)

3

Parrots

5%

(3/63)

4

Armadillos

5%

(3/63)

5

Rabbits

5%

(3/63)

L 2 D

Select Answer to see Preferred Response

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Evidences (2)
Topic COMMENTS (2)
Private Note