Slayt 1

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SUPERFICIAL MYCOSES Assoc.Prof.Dr.Yesim Gürol

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Learning Objectives

• To list dermatophytes
• To list subcutaneous mycoses

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• infections caused by
• dermatophytic fungi (dermatophytosis)
• Nondermatophytic fungi (dermatomycosis)

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DERMATOPHYTOSES

• Trichophyton
• Epidermophyton
• Microsporum
• cause disease in animals and/or humans.
• have the ability to invade the skin,hair or
  nails.
• keratinophylic and keratinolytic.
• invade upper outermost layer of epidermis

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dermatophytosis
tineas
ringworm
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Morphology and Identification

• identified by
• colonial appearance
• microscopic morphology
• Growth at Sabourauds dextrose agar at 25oC for
  two weeks

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Epidermophyton floccosum
Microsporum canis
Microsporum audouinii
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Microsporum persicolor
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Trichophyton spp.
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Epidemiology and immunity

• Begins in the skin after trauma and contact
• Host susceptibility depends on
• Moisture
• Warmth
• Spesific skin chemistry
• Composition of sebum and perspiration
• Youth
• Heavy exposure
• Genetic predisposition

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• Dermatophytes are classified as anthropophilic,
  zoophilic or geophilic according to their normal
  habitat.
• Anthropophilic
• human hosts
• mild, chronic inflammation.
• Zoophilic
• primarily in animals
• inflammatory reactions in humans who have contact
  with infected cats, dogs, cattle, horses, birds,
  or other animals.
• followed by a rapid termination of the infection
• Geophilic
• from the soil
• occasionally infect humans and animals.
• They cause a marked inflammatory reaction, which
  limits the spread of the infection and may lead
  to a spontaneous cure but may also leave scars.

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• Contagious
• Frequently transmitted by exposure to shed skin
  scales, nails or hair containinh hyphae or conidia

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• Tinea capitis
• Tinea favosa
• Tinea corporis
• Tinea pedis
• Tinea manuum
• Tinea imbricata
• Tinea cruris
• Tinea barbae
• Tinea nigra
• Tinea ungium

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Tinea capitis

• infection of the scalp with a dermatophyte
  fungus.
• Hair can be infected with Trichophyton
  (abbreviated as "T".) and Microsporum ("M".)
  fungi.
• classified according to how the fungus invades
  the hair shaft
• Ectothrix infection
• The fungal branches (hyphae) and spores
  (arthroconidia) cover the outside of the hair.
• Ectothrix infections can be identified by Woods
  light (long wave ultraviolet light) examination
  of the affected area the vet uses this to check
  your cats fur.
• Endothrix infection
• The hair shaft is filled with fungal branches
  (hyphae) and spores (arthroconidia).
• Endothrix infections do not fluoresce with Woods
  light.
• Favus
• caused by T. schoenleinii infection
• honeycomb destruction of the hair shaft

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macroconidia
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• When the hair is infected,
• ectothrix
• endothrix
• favic

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• Tinea capitis may present in several ways.
• Dry scaling like dandruff but usually with
  moth-eaten hair loss
• Black dots the hairs are broken off at the
  scalp surface, which is scaly
• Smooth areas of hair loss
• Kerion very inflamed mass, like an abscess
• Favus yellow crusts and matted hair
• Carrier state no symptoms and only mild scaling

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Trichophytid reaction (id reaction)

• The patient may become hypersensitive to
  constituents or products of the fungus and
  develop allergic manifestations
• Usually vesicles
• Mostly on the hands
• No fungi present in lesion

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Tinea capitis
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Tinea capitis caused by Trichophyton
mentagrophytes
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Tinea barbae
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Tinea pedis (Athletes foot)
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Tinea corporis
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Tinea unguium (onychomycosis)
Tinea ingualis (cruris) (jock itch)
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SUBCUTANEOUS MYCOSES

• Normally reside in soil or vegetation
• Enter the skin or subcutaneous tissue by
  traumatic inoculation with contaminated material
• Sporotrichosis
• Chromoblastomycosis
• Eumycotic mycetoma
• Subcutaneous zygomycosis
• Subcutaneous phaeohyphomycosis

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SPOROTRICHOSIS

• Sporothrix schenkii
• Thermally dimorphic
• Usually sporadic
• Most common in warmer climates
• Outbreaks related to forest work, mining,
  gardening
• Classic infection traumatic inoculation of soil
  or vegetable or organic matter contaminated with
  fungus
• Zoonotic transmission with armadillo hunters and
  infected cats

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• Chronic infection
• Nodular and ulcerative lesions that develop along
  lymphatics
• grossly may resemble a malignant process
  squamous cell carcinoma
• Dissemination to other sites rare
  !(bones,eyes,lungs, central nervous system)

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• Specimens
• Biopsy
• Exudate from lesions
• Culture

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S.schenckii
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Chromoblastomycosis (chromomycosis)

• chronic fungal infection
• slow growing verrucous nodules or plaques
• mostly in tropics
• Pigmented fungi (dematiaceous fungi)

• Fonsecaea
• Cladosporium
• Exophiala
• Cladophialophora
• Rhinocladiella
• Phialophora

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• into the skin by trauma
• Verrucous, wart like lesions
• Cauliflower like nodules
• Rarely elephanthiasis

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Subcutaneous phaeohyphomycosis

• Darkly pigmented septate hyphae in tissue
• Cutaneous and systemic infections
• Solitary encapsulated cysts in the subcutaneous
  tissue
• Sinusitis
• Brain abscesses (usually fatal)
• All exogenous molds that normally exist in nature

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phaeohyphomycosis

• Exophiala,
• Phialophora,
• Wangiella,
• Bipolaris,
• Exserohilum,
• Cladophialophora ,
• Phaeoannellomyces,
• Aureobasidium,
• Cladosporium,
• Curvularia
• Alternaria

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MYCETOMA

• Local swelling of infected tissue and
  interconnecting
• Often draining
• Sinuses or fistulae that contain granules
• Actinomycetoma....mycetoma caused by an
  actinomycete
• Eumycetoma....(Madura foot, maduromycosis)
  mycetoma caused by a fungus
• Clinical features similar
• Treatment different
• Actinomycetomas more invasive

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MYCETOMA
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• After traumatic inoculation with soil
  contaminated with one of these agents
• Feet, lower extremities, hands and exposed areas
• Suppuration, abscesses, granules,
• Contagious muscle and bone
• Deformation, loss of function
• Very rarely foreign body (e.g.cardiac pacemaker)
  infection