MYCOVIRO - SUPERFICIAL, CUTANEOUS, SUBCUTAENOUS MYCOSIS

• The least invasive of the pathogenic fungi are the dermatophytes and other superficial fungi that are

  adapted to the keratinized outer layers of the skin.
• The main reason why we treat them is because of their unsightly appearance.
• The manifestation vary depending on the site of infection and vigor of the host response, but they often involve erythema (redness of the skin), induration, itching, and scalling.
• The most familiar name is “RINGWORM,” describing the annular shape of the advancing edge of this cutaneous infection.
• Superficial Mycoses Agent – affects the epidermis
• Cutaneous Mycoses Agent – affects the dermis
• SUPERFICIAL MYCOSES AGENT

  • Mallassezia spp.
  • Hortaea weneckii
  • Piedraia hortae
  • Trichosporon spp.
• CUTANEOUS MYCOSES AGENT

  • Microsporum spp.
  • Trichophyton spp.
  • Epidermophyton floccosum
• Malassezia species ● appears as tight clusters of spherical yeast like cells “spaghetti with meatballs” microscopically
• Malassezia species

  Mycosis caused : Pityriasis (tinea) Versicolor
• Pityriasis (tinea) Versicolor

  • is a very common superficial fungal infection of the skin.
  • It is characterized by discrete patches of either hypopigmentation (decrease pigment or color of the skin) or hyperpigmentation (increase in skin pigmentation) especially on the skin of the torso and upper arms.
• the vast majority of cases of pityriasis versicolor are caused by Malassezia globose, Malassezia furfur, or Malassezia sympodialis
• Hortaea weneckii ● Brown to dark olivaceous, septate hyphal elements and numerous two-celled, pale brow, cylindrical to spindle-shaped yeast-like cells that taper towards the ends to form an annellide
• Hortaea weneckii

  Mycosis caused: Tinea nigra (or Tinea nigra palmaris)
• Tinea nigra (or Tinea nigra palmaris)

  • Is a superficial chronic and asymptomatic infection of the stratum corneum caused by the dematiaceous fungus Hortaea (Exophiala) werneckii. The lesions appear as a dark (brown to black) discoloration, often on the palm.
• Piedraia hortae

  • Appears as short, Dark hyphae containing thick-walled resting cells.
  • Ascomata consist of irregularly shaped pseudothecia that are black in color. Each ascoma contains a single ascus containing eight ascopores.
• Piedraia hortae

  Mycosis caused: Black Piedra
• Black Piedra ○ Causative agent of black piedra which is a nodular infection of the hair shaft.
• Trichosporon spp. ● Trichosporon cutaneum ● Trichosporon beigelli ● Trichosporon asahii
• Trichosporon spp.

  Mycosis caused: White Piedra
• Trichosporon spp.

  • produces pleomorphic (varying shapes) yeast cells, measuring 3–8 μm in diameter, septate hyphae, and arthroconidia either of which can predominate. The organism can readily be confused with Candida spp.
• White Piedra

  light brown soft nodules on the beared or mustache
• Cutaneous mycoses are caused by fungi that infect only

  the KERATINIZED tissue (skin, hair, and nails).
• Cutaneous Mycoses Agent

  • Microsporum
  • Trichophyton
  • Epidermophyton
• Dermatophytosis, begin when the infecting fungus comes in contact with skin, especially if there are minor breaks in the skin integrity
• Detached hair and skin scales containing dermatophytes can remain infectious for months in the environment.
• Once the stratum corneum is penetrated, the organism can proliferate in the keratinized layers of the skin, with a variety of proteinase helping to establish infection.
• Proteinase an enzyme that will degrade protein which allows fungi to establish infection in the keratin layer.
• Tinea capitis - Scalp
• Tinea pedis - Feet, Athlete’s Foot
• Tinea manuum - Hands
• Tinea cruris - Groin
• Tinea barbae - Beard, Hair
• Tinea unguium - Nail Beds
• Tinea pedis (Athlete’s Foot) is caused by:

  (1) Trichophyton rubrum

  (2) Epidermophyton floccosum

  (3) Trichophyton mentagrophytes
• Trichophyton mentagrophytes - micro spores as small and globose arranged in grapelike clusters
• Tinea pedis is the most prevalent of all dermatophytosis. It usually occurs as a chronic infection of the toe webs.
• The skin of the toe webs becomes macerated and peels, whereupon cracks appear that are prone to develop secondary bacterial infection
• Tinea unguium (Onchomycosis)

  • Nail infection may follow prolonged tinea pedis. With hyphal invasion, the nails become yellow, brittle, thickened, and crumbly. One or more nails of the feet or hands may be involved
• Tinea unguium (Onchomycosis) is caused by:

  • Trichophyton mentagophytes
  • Trichophyton rubrum
  • Epidermophyton floccosum