Sporothrix schenckii

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Sporothrix schenckii
Slide Culture Potato Dextrose Agar Room
Temperature
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Sporotrichosis

• Identification of S. schenckii
• With age the conidia develop down the
  conidiophore and along the hyphae like birds on a
  wire (en thyrse)
• Older conidia along the hyphae become dark brown
  or even black

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Chromoblastomycosis

• Etiology
• Many species of dematiacious hyphomycetes cause
  chromoblastomycosis
• Some texts categorize this organism in a group
  filamentous fungi and others as
  phaeohyphomyecetes although the pathology is
  clearly subcutaneous in nature
• Most common species are Cladosporium
  (Cladophialophoria) carionii, Fonsecae pedrosoi,
  and Phialophora verrucosa. Lets remember the
  first organism name as an agent of
  Chromoblastomycosis.

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Epidemiology

• All fungal causes of this disease grow readily
  in the environment
• Etiologic agents are found in soil, decaying
  wood, and other vegetation
• Infections are caused by traumatic implantation
  of fungal elements in the skin
• It is an occupational hazard of farmers and
  manual laborers
• World-wide distribution but more common in bare
  footed populations living in tropical regions.
  Also common in timber and cattle workers in humid
  areas of Australia.

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Chromoblastomycosis

• Clinical manifestations
• Causes epidermal pathology which is chronic,
  slowly progressive and localised. Early lesions
  are crusted, painless and pruritic. Lesion
  formation occurs over a period of years.
• Hyperplasia resulting from granulomatous immune
  response causes lesions to become raised or
  tumorous, developing dark sclerotic red spots
• Eventually tissue proliferation produces crusted
  and wart-like resembling a head of cauliflower.

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Clinical manifestations

• Satelite lesions occur via lymphatic spread to
  adjacent areas
• There is no really successful therapy. Excision
  and local heat have been used with some success.

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Chromoblastomycosis
Typical lesions on the foot and hand
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cauliflower lesions
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Chromoblastomycosis

• Laboratory Identification
• The cardinal sign of chromoblastomycosis is the
  tissue form seen in biopsy
• It is a round structure known as a sclerotic
  body
• It is dark brown to black with internal cross
  cleavages giving it a berry (or muriform)
  appearance hyphae may also be present
• It can be seen in KOH preps or stained histology
  sections