Bartonella henselae: Difference between revisions

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Bartonella henselae
(initial creation with brief epidemiology and presentation)
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==Clinical Presentation==
 
==Clinical Presentation==
* Classic cat-scratch disease is a self-limited febrile illness with [[Causes::regional lymphadenopathy]]
+
* Typical cat-scratch disease is a self-limited febrile illness with [[Causes::regional lymphadenopathy]]
  +
** Following an incubation period of 3 to 10 days, and initial pustule develops at site of inoculation which may last for up to 3 weeks
  +
** This is followed in 1 to 7 weeks by ipsilateral [[Causes::lymphadenopathy]] (usually the head or neck)
  +
*** May involve one or more lymph nodes
  +
*** May drain pus
  +
*** Will eventually resolve, over months or longer
  +
** There may be a concurrent low-grade [[Causes::fever]] for several days, with [[Causes::malaise]] or [[Causes::fatigue]]
  +
** May have [[Causes::headache,]] sore throat, transient rash, or, rarely, [[Causes::erythema nodosum]]
  +
** May have mild leukocytosis (neutrophils or eosinophils)
  +
* CSD may be complicated by [[Causes::encephalopathy]] in 2 to 4% of cases
  +
** Headache is common, and they may develop seizures and neurologic deficits
  +
** Resolves over weeks to months (to as long as a year)
  +
** CSF is usually normal, although lymphocytic pleiocytosis and elevated protein are seen in one third
  +
** MRI brain is almost always normal
  +
** EEG is nonspecific
  +
** Proportionally less common in children
 
* Other syndromes include:
 
* Other syndromes include:
** Parinaud oculoglandular syndrome, with granulomatous conjunctivitis and ipsilateral regional lymphadenopathy
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** [[Causes::Parinaud oculoglandular syndrome]], with granulomatous conjunctivitis and ipsilateral (usually preauricular) lymphadenopathy
** Neuroretinitis and other ophthalmic complications
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** [[Causes::Neuroretinitis]] and other ophthalmic complications
** Fever of unknown origin, in children
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** [[Causes::Fever of unknown origin]], in children
** Culture-negative endocarditis in patients with existing valve abnormalities
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** Culture-negative [[Causes::endocarditis]] in patients with existing valve abnormalities
** Chronic endocarditis, with vasculitis and glomerulonephritis
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** Chronic endocarditis, with [[Causes::vasculitis]] and [[Causes::glomerulonephritis]]
* Disseminated disease is possible in immunocompromised patients, including bacteremia, disseminated skin lesions, and hepatsplenic lesions
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* Disseminated disease is possible in immunocompromised patients, including bacteremia, disseminated skin lesions, and hepatosplenic lesions
  +
  +
==Diagnosis==
  +
* Histopathology of node aspirate shows nonspecific inflammation, with granulomas and stellate ncerosis
  +
** Microabscesses are classic finding
  +
** Bacilli may be seen with Warthin-Starry staining
  +
* PCR of node aspirate is the best and most sensitive test
  +
* Serology for acute and convalescent titres
   
 
{{DISPLAYTITLE:''Bartonella henselae''}}
 
{{DISPLAYTITLE:''Bartonella henselae''}}

Revision as of 21:06, 15 May 2020

Background

  • Causes cat-scratch disease

Epidemiology

  • Present worldwide
  • Main reservoir is cats, and especially kittens
  • Infections are more common in children, likely due to increased exposure to kittens
  • Transmitted to humans by inoculation of cat flea (Ctenocephalides felis) feces into a cat scratch or bite

Clinical Presentation

  • Typical cat-scratch disease is a self-limited febrile illness with regional lymphadenopathy
    • Following an incubation period of 3 to 10 days, and initial pustule develops at site of inoculation which may last for up to 3 weeks
    • This is followed in 1 to 7 weeks by ipsilateral lymphadenopathy (usually the head or neck)
      • May involve one or more lymph nodes
      • May drain pus
      • Will eventually resolve, over months or longer
    • There may be a concurrent low-grade fever for several days, with malaise or fatigue
    • May have headache, sore throat, transient rash, or, rarely, erythema nodosum
    • May have mild leukocytosis (neutrophils or eosinophils)
  • CSD may be complicated by encephalopathy in 2 to 4% of cases
    • Headache is common, and they may develop seizures and neurologic deficits
    • Resolves over weeks to months (to as long as a year)
    • CSF is usually normal, although lymphocytic pleiocytosis and elevated protein are seen in one third
    • MRI brain is almost always normal
    • EEG is nonspecific
    • Proportionally less common in children
  • Other syndromes include:
  • Disseminated disease is possible in immunocompromised patients, including bacteremia, disseminated skin lesions, and hepatosplenic lesions

Diagnosis

  • Histopathology of node aspirate shows nonspecific inflammation, with granulomas and stellate ncerosis
    • Microabscesses are classic finding
    • Bacilli may be seen with Warthin-Starry staining
  • PCR of node aspirate is the best and most sensitive test
  • Serology for acute and convalescent titres