SUBCUTANEOUS MYCOSES Sevtap Arikan, MD
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SUBCUTANEOUS MYCOSES
Sevtap Arikan, MD
SUBCUTANEOUS MYCOSESSporotrichosisChromoblastomycosis MycetomaRhinosporidiosisLobomycosis
SPOROTRICHOSISGeneral features
Chronic inf. involving cutaneous, subcutaneous and lymphatic tissue
Frequently encountered in gardeners May develop in otherwise healthy
individualsMost common in Mexico, endemic in
Brasil, Uruguay, South Africa
SPOROTRICHOSISCausative agent
Sporothrix schenkiiThermally dimorphicNatural habitat: soil
37°C: Round/cigar-shaped yeast cells25°C: Septate hyphae, rosette-like clusters of conidia at the tips of the conidiophores
SPOROTRICHOSISPathogenesis & Clinical FindingsSkin: Follows minor traumaNoduleulcer necrosisSkin/subcutaneous tissue lymphatic channels lymph nodes
Systemic dissemination: Bones, joints, meninges
Primary pulmonary: Chronic alcoholics
SPOROTRICHOSISDiagnosisSamples: Aspiration fluid, pus, biopsyI. Micr. Direct microscopic examination
(KOH), histopathological examination (methenamine silver stain)Yeast cells, asteroid body
II.CultureIII.Serology Yeast agglutination testIV. Sporotrichin skin test (?)
SPOROTRICHOSISTreatmentSpontaneous healing is
possible.
Cutaneous inf.: Potassium iodide (Topical/oral)
Disseminated inf.: Amphotericin B
CHROMOBLASTOMYCOSISGeneral features
Posttraumatic chronic inf. of subcutaneous tissue
Papules verrucous cauliflower-like lesions on lower extremities
Systemic invasion is very rare
CHROMOBLASTOMYCOSISCausative agents1. Fonsecaea 2. Phialophora 3. Cladosporium
Pigmented (dematiaceous) fungi in soil Arrangement and shape of the spores vary from one
genus to other
CHROMOBLASTOMYCOSISDiagnosis
Direct microscopic examination (KOH)Sclerotic body
CultureSabouraud dextrose agar, 4-6 weeks, 37°C
CHROMOBLASTOMYCOSISTREATMENTSurgeryAntifungal therapy (susceptibility
varies depending on the genus)Amphotericin BFlucytosineKetoconazole
Heat
MYCETOMA(=Maduromycosis=Madura foot)
Posttraumatic chronic inf. of subcutaneous tissue
Common in tropical climates Causative agents
Saprophytic fungi (Eumycetoma)Actinomyces (Actinomycetoma)
MYCETOMACausative agentsMadurella mycetomatis Pseudallescheria boydiiAcremonium Exophiala jeanselmeiLeptosphaeriaAspergillusActinomyces
MYCETOMAClinical findings
Site(s): Feet, lower extremities, hands
Findings: Abscess formation, draining sinuses containing granules Deformities
Dissemination: Muscles and bones
MYCETOMADiagnosis
Clinical findings are nonspecific
Identification of the infecting fungus is difficult
Characteristics of the granule, colony morphology, and physiological tests are used for identification
EUMYCETOMATreatment
SurgeryAntifungal therapy
Amphotericin BFlucytosineTopical nystatin Topical potassium iodide(choice of treatment varies according to the infecting fungus)
RHINOSPORIDIOSISGeneral & Clinical featuresChronic inf.In diversPolypoid masses at nasal mucosa,
conjunctiva, genitalia and rectumSeropurulent discharge from nasal
lesions
RHINOSPORIDIOSISCausative agent
Rhinosporidium seeberiNatural reservoir: fish, aquatic
insects Spherules filled with endospores (in
tissue) Has not been cultured in vitro on
artificial media
RHINOSPORIDIOSISTreatmentSurgery
Ethylstilbamidine(Local injection)
LOBOMYCOSISPathogenesis & Clinical features
Chronic, subcutaneous, progressive inf. Traumatic inoculation of the fungusNatural inf.: in dolphinsHard, painless nodules on extremities,
face and earVerrucous / ulcerative lesionsLesions mimic those of
chromoblastomycosis, mycetoma and carcinoma
LOBOMYCOSISCausative agent
Loboa loboiMultiple budding yeast cells
forming short chains Asteroid body
Has not been cultured in vitro on artificial media
LOBOMYCOSISTreatment
Surgery
ClofazimineAmphotericin BSulphonamides