Subcutaneous Mycoses

• Subcutaneous mycoses are Caused by saprophytic fungi found in the soil or decaying vegetation
• Acquired through traumatic implantation/inoculation of the organism into the subcutaneous tissue
• Superficial cut or abrasion may introduce an environmental mold with the ability to infect the exposed dermis
• Subcutaneous Phaeohyphomycosis is caused by darkly pigmented fungi such as Hyphomycetes, Coelomycetes, and Ascomycetes
• Mode of transmission of Phaehyphomycosis is direct traumatic implantation
• Sporothrix schenckii is a dimorphic fungus found worldwide in plants, soil, and decaying vegetation. It is considered as an occupational hazard.
• Sporothrix schenckii Causes Rose gardener's disease when traumatically introduced into the skin. It is a chronic granulomatous infection that is rarely seen in pus and tissues from human infection.
• Sporothrix schenckii Produces two types of conidia: thin-walled conidia arranged around the apex of the conidiophore and thick-walled dark sessile conidia attached directly to the hyphae
• Chromomycotic agents, also known as Chromoblastomycosis, have melanized cell walls
• Agents include Phialophora verrucosa, Fonsecaea pedrosoi, Cladosporium carrionii, Fonseca compact, and Rhinocladiella aquaspersa
• Chromomycosis or chromoblastomycosis In tissue produces spherical brown cells termed muriform or sclerotic bodies ( black granules/ copper pennies)
• Chromomycosis Affects immunocompetent individuals living in tropical areas, causing chronic, granulomatous verrucosa ulcerative infections
• Maduromycotic agents cause mycetoma, a chronic granulomatous infection characterized by painless subcutaneous masses with multiple sinuses draining pus and grains. White, yellow, red or. black granules are extruded in pus.
• Often confined to hands or feet, known as Madura foot, in immunocompetent individuals in contact with contaminated soils
• A definitive diagnosis of mycetoma is achieved by demonstrating grains or granules in tissue biopsy or draining exudates
• Subcutaneous mycoses involves fungal infection beneath the skin.

  involve deeper skin layer commonly chronic.
• Lymphocutaneous sporotrichosis: Papule at the portal of entry that may ulcerate and spread the pathogen through the regional lymphatics that could result in a serious of lesions progressing at the affected limb.
• Fixed sporotrichosis: Less progressive wherein they confined only on the site of inflammation.
• Sporothrix schenckii: Tissue form/ yeast form (37C- BHIB w/blood)

  3-5 um usually spherical, multiple budding cells, cigar-shape

  Gram + cigar-shaped bodies within the PMN (Polymorphonuclear cells- neutrophils, basophils and eosinophils)
• Sporothrix schenckii: Mold grows best at 27C

  Room temperature but not in 25C

  Tear drop shaped conidia in “floweret” or “sleeve” arrangement
• Asteroid body: hapoens in cases of sporotrichosis; forms in the tissue.
• Chromomycosis or chromoblastomycosis

  colonies: olive gray to browm to black
• Subcutaneous phaeohyphomycosis: caused by darkly pigmented fungi.

  Masson—Fontana stain is presumptive for the diagnosis of phaeohyphomycosis.
• 4 types of Subcutameous phaeohyphomycosis:

  • Exophiala jeanselmei
  • Phialophora richardsiae
  • Bipolaris spicifera
  • Wangiella dermatitidis
• Phialophora verrucosa

  Specialized conidiophores are vase-shape Flask-shaped or tubular phialides with flared tips or with cup-shaped collarets
• Fonsecaea pedrosoi: most common causative agent of Chromoblastomycosis
• Cladosporium type - Chained spores Acrotheca type - Terminal swollen sporulation Phialophora type - vase or flask shape (clusters)
• Cladosporium carrionii Also known as Cladophialophora.

  produce elongated with long branching chains of oval conidia by distal (acropetalous) budding.
• Fonseca compactum: Characterized by formation of terminal and lateral conidiophores bearing compact masses of long, branching chains of spherical conidia.
• Maduromycotic: White, yellow, red or. black granules are extruded in pus.
• The diagnosis of Mycetoma should never be made unless granules are seen