U3 LEC: SUPERFICIAL MYCOSES Flashcards
Infections confined to the outermost layer of skin or hair
Superficial Mycoses
Superficial mycoses are infections confined to the?
outermost layer of skin or hair
Skin infections
Tineas
Hair infections
Piedras
T/F: Superficial mycoses do not show overt symptoms.
True
Latin, meaning worm
Tinea
Clinical manifestation of Malassezia furfur
Tinea versicolor
Tinea versicolor is caused by?
Malassezia furfur
Tinea versicolor is also known as?
Pityriasis versicolor
Tinea versicolor
Lesions
Patchy lesions or scaling of varied pigmentation
Tinea versicolor
Thought to be cause of?
dandruff
T/F: Tinea versicolor affects all ages.
True
Tinea versicolor
May involve what areas?
any area but primarily:
- face
- chest
- trunk
- abdomen
Tinea versicolor
Patches in darkly pigmented skin
Pale patches
Tinea versicolor
Spots in fair skin
Fawn-colored liver spots
Tinea versicolor
Evident in?
warm months
Common endogenous skin colonizer
Malassezia furfur
M. furfur is ____philic
lipo
Appearance of M. furfur
spaghetti and meatballs
M. furfur
Epidemiology
worldwide, hot, humid and tropical locations
M. furfur
Risk factors
- receiving corticosteroid therapy
- genetic influence
- poor nourishment
- excessive sweating
M. furfur
Treatment
- antidandruff shampoos
- removal of indwelling feeding lines (lipid replacement therapy, infants)
- selenium sulfide
- topical or oral azoles
M. furfur
Daily applications of?
selenium sulfide
Clinical manifestation of Hortaea werneckii
Tinea nigra
Tinea nigra is caused by?
Hortaea werneckii
Tinea nigra
Appearance
Brown to block non-scaly macules
Tinea nigra
Occur most often on?
palms and soles
T/F: Misdiagnosis in Tinea nigra
does not occur.
False
can occur
Tinea nigra
Epidemiology
Tropical areas of
- Central and South America
- Africa
- Asia
H. werneckii is formerly known as?
- Phaeoannellomyces werneckii
- Exophiala werneckii
H. werneckii
Rate of growth in common fungal media
very slow
H. werneckii is what kind of fungus?
Dematiaceous
H. werneckii
Treatment
- Keratolytic solutions
- Salicylic acid
- Azole antifungal drugs
Clinical Manifestation of Piedraia hortae
Black piedra
Black piedra is caused by?
Piedraia hortae
Black piedra
Infection of the?
hairs of the scalp
Black piedra
Appearance of nodules
Hard, dark brown to black
Black piedra
The nodules are firmly attached to the?
hair shaft
Black piedra
Epidemiology
Tropical areas:
- Africa
- Asia
- Latin america
P. hortae
Treatment
- Removal of infected hair
- Topical antifungal agent
Clinical manifestation of Trichosporon spp.
White Piedra
White Piedra is caused by?
Trichosporon spp.
White Piedra
Occurs on?
hair shaft
White Piedra
Appearance of mycelia
Soft mycelial mat
White Piedra
Soft mycelial mat surrounds?
- hair of the scalp
- face
- pubic region
White Piedra
Epidemiology
Tropical areas
- South America
- Africa
- parts of Asia
No longer a valid species infecting humans
Trichosporon beigelii
Implicated in most cases of superficial mycoses
- T. ovoides
- T. asteroids
- T. cutaneum
- T. inkin
Severe and frequently fatal disease in immunocompromised hosts
T. asahii
Causes meningitis
T. mucoides
Occasionally found as part of normal skin biota
Trichosporon spp.
Trichosporon spp.
Isolated from?
animals and soil
Trichosporon spp.
Recognized as
opportunistic systemic pathogens
Trichosporon spp.
under Opportunistic systemic pathogens
- frequently fatal
- occur in immunocompromised host
- hematologic disorders or malignancies
- undergoing chemotherapy
Trichosporon spp.
Treatment
- removal of infected hair
- topical antifungal agent