ODR

What are the organisms that cause superficial mycoses, and what condition do they cause?
Malassezia: tinnea versicolor, seborrheic dermatitis
Exophiala: tinnea nigra
Where is Malassezia found?
normal flora of skin rich in sebaceous glands
it is lipophilic
What organism causes hyper/hypopigmented, easily scaled, macular lesions, usually on the upper torso?
malassezia (tinnea versicolor)
What organism causes seborrheic dermatitis?
malassezia
What organism appears as “spaghetti and meatballs” with KOH staining?
malassezia
How does seborrheic dermatitis present?
pruritic, erythematous, greasy-appearing patches and scales (usually facial)
What causes darkened, non-scaling macular lesions on the palms/soles?
tinnea nigra (exphiala)
What causes hard black nodules on the hair shaft?
piedraei hortae (black piedra)
What causes white-creamy yellow soft granules on the hair?
white piedra (trichosporon cutaneum)
How are superficial mycoses treated?
topical keratinolysic agents and/or antifungals (mecanazole), personal hygiene
What organisms are reponsible for tinea capitis?
t. tonsurans
m. andwinii
m. canis
List the cuteanous mycoses.
tinea capitis (gray patch ringworm–loss of hair)
tinea pedis (athlete’s foot)
tinea cororpis: ringworm of body
tinea cruris: groin (jock itch)
Tinea Unguium: nail (onchomycosis)
tinea barbae: beard
What organisms are repsonsible for athlete’s foot?
E. floccosum
T. Rubrum
T. mentagrophytes
trichosporon cutaneum
white piedra
t tonsurans
m andwinii
m canis
tinea capitis
Which mycoses are keratinophilic, and what are the subtypes?
cutaneous mycoses (epidermophyton, trichophyton, microsporum)
What are the 2 types of subcutaneous mycoses?
sporothrichosis
chloroblastomycosis
How is sporotrichosis transmitted?
traumatic inoculation
Describe the lesion seen with sporotrichosis.
subcutaneous nodule –> ulcer
What are some characteristics of chloroblastomycosis?
slow development of verrucous, cutaneous nodular lesions: cauliflower-like appearance w/intense hyperplasia
sclerotic bodies
What exhibits wart-like growths along lymphatics of leg or feet?
chloroblastomycosis
What fungal infection causes elphantiasis?
chloroblastomycosis
What causes mucosal fungal infections?
candidiasis
How is candidiasis diagnosed?
yeast & hyphae
gram (+)
germ tube formation
What are the predisposing risk factors for candidiasis?
elderly, infants, endocrine disorders, broad spectrum Abs, burns, IV drug abuse, AIDS, immunodef, leukemia/hemat malignancy, indwelling cath, immunosuppression
e. floccosum
t. rubrum
t. mentagrophytes
tinea pedis
What is the morphology of candidasis?
budding yeast
in vivo: dimorphic
germ tube formation
candidiasis
Categories: Microbiology