sup mycoses and dermato Flashcards
Chronic superficial fungal infection of the palms (disease & agent)
Tinea nigra, Exophiala werneckii
2-celled yeast cell
Exophiala werneckii
color of tinea nigra in the skin
brown to black macules
diameter of tinea nigra
1-5cm
Abundant aerial mycelia and become velvety, dark olivaceous in colour
mature mould
Initially colonies are mucoid, yeast-like and shiny black.
young yeast)
Management & Treatment of tinea nigra
Sulfur soap, salicylic acid, azoles
Topical treatment
o Whitfield’s ointment (benzoic acid compound)
o Imidazole agent twice a day for 3-4x a week
Hyper- or hypopigmented of the skin.
Tinea/Pityriasis Versicolor
“Fawn-colored macules”
Tinea/Pityriasis Versicolor
lipophilic basidiomycetous yeasts
Malassezia furfur
Found as a normal flora on the skin
Malassezia furfur
Follicular papules and pustules
Pityrosporum folliculitis
fungal acne
Pityrosporum folliculitis
Degradation of sebum and consumption of fatty acids
Seborrheic dermatitis
common among infants as venous IV catheter acquired
Systemic Infection (M. furfur)
Has the ability to changes in quantity and composition of sebum due to Malassezia spp.
Seborrheic dermatitis
erythema and scaling in areas with a rich supply of sebaceous glands
Seborrheic dermatitis
Yeast cells look like phialioconidium
Malassezia furfur
looks like Spaghetti & Meatballs under the microscope
Malassezia furfur
short septate hyphae in short chain
Malassezia furfur
epidemics in families
Black Piedra
Sources of fatty acids:
natural oil and olive oil
culture containing cycloheximide (Acti-dione) with olive oil
Sabouraud’s dextrose agar or Sheep blood agar
Chronic fungal infection of the hair shaft (disease and agent)
Piedraia hortae (Black piedra)
hyphal elements
thin part
superficial cosmetic fungal infection of the hair shaft
trichosporon ovoides/ white piedra
agar containing glycerol mono-oleate
Dixon’s agar
irregular, soft, white or light brown nodules firmly adhering to the hairs
White piedra
has Arthroconidia and Blastoconidia
Trichosporon ovoides/white piedra
white or yellowish to deep cream colored
Trichosporon ovoides/ white piedra
fungal cells cemented together
Thick part
source of fatty acid in Dixon agar
oleic acid
Ascomycetous fungus
Piedraia hortae (Black piedra)
old name of Trichosporon ovoides
Trichosporon beigelii
topical treatment of Trichosporon beigelii
imidazole agent
Colonies are greenish black
Piedraia hortae (Black piedra)
smooth, wrinkled, velvety, dull colonies with a mycelial fringe.
Trichosporon ovoides/ white piedra
its culture Take about 21 days
Piedraia hortae (Black piedra)
use keratin as a source of
nitrogen
between fingers
manuum
length of white piedra
1.0 - 1.5 mm in length
“ringworm” disease (mycotic infection) of
the nails, hair, and/or stratum corneum of the skin caused by fungi called
Dermatophytoses
primary isolation media of white piedra
Yeast base agar
major protein found in horns, hooves,
nails, hair, and skin.
Keratin
scalp & eyebrows
Tinea capitis
demonstrate pigment
production by Trichophyton rubrum
Potato dextrose agar
more general name for any skin disease
caused by a fungus
Dermatomycoses
ringworm in feet
pedis
genitalia
cruris
special form of Tinea corporis usually
concentric rings on skin
imbricata
rinbgworm in face
fascie
rinbgworm in fingernails
unguium
hairy parts of face
Tinea barbae
face, arms, trunks
corporis
no scaling
Alopecia areata
(agar) T. rubrum (-) is differentiated from T. mentagrophytes (+) by amount of pigment produced
Corn meal agar (CMA) + 10% glucose:
diffuse hair loss
Seborrheic dermatitis
antibody that is activated when exposed to mold and attaches to mast cells
igE
no loss of hair, silvery scaling
Psoriasis
Laboratory Tests for Dermatophytes
Direct Microscopy using
10% KOH or 20% КОН
Apple green fluorescence of ectothrix hair
Microsporum audouinii
negative in Hair Baiting Test
T. rubrum and m equinum
obverse color Microsporum audouini
gray to tan white
cinnamon color, powdery colonies
Microsporum gypseum
3-9 celled, broadly spindle-shaped, rough walled macroconidia
. Microsporum gypseum
reverse color Microsporum audouini
light salmon with red brownish center
thin colonies with feathery
edge; center of colony is white to buff, edges are orange yellow
Microsporum canis
lemon yellow/yellow orange
Microsporum canis
beak-like shaped rough
macroconidia
Microsporum canis
Green yellow fluorescence of ectothrix hair
Microsporum canis
Center of colonies tend
to be folded, khaki
green to yellow color
Epidermophyton floccosum
moderately thick, smooth walls (beaver tails)
Epidermophyton floccosum
White, pink, granular, fluffy colonies;
with occasionally light yellow periphery
mentagrophytes
reverse: yellow brown
with folds
Epidermophyton floccosum
White downy-pink granules, rugal folds
are common
rubrum
Favic chandeliers and chlamydospores
common
schonleinii
Source of infection of Epidermophyton floccosum
Sharing of linens, towels or clothes
Athletes, soldiers, ship crews
White, tan-yellow or rust, suede like to
powdery. Wrinkled and heaped or sunken
crater
tonsurans
Irregularly hip, smooth, white cream with
radiating grooves
schonleinii
Port-wine/deep violet, heaped on flat
with waxy surface
violaceum
Macronidia: few, smooth walled, cigar
shaped, connected to hyphae with
definite narrow attachment
mentagrophytes
Micronidia: spherical often in grape-like
clusters spiral hyphae
mentagrophytes
Macroconidia: few, smooth-walled,
pencil-shaped
rubrum
Microconidia tear shaped and lateral
along hyphae
rubrum
“Balloon Forms”- aged pleomorphic
microconidia
tonsurans
Swollen hyphae containing cytoplasmic
granules
violaceum
Microconidia: large, clavate, lateral
verrucosum
Macroconidia: “rat tail”, 3-5 cells thin
walled
verrucosum
Often start on the scrotum and spread to the groin as dry, itchy lesions
Tinea cruris or “jock itch”
Tinea unguium and
tinea cruris are often
caused by this fungus.
Epidermophyton floccosum
Arthroderma otae
Microsporum canis
Atypical vegetative hyphae with terminal
chlamydospore
microsporum audouinii
rare
tinea nigra and black piedra
common
versicolor, seb dermititis and follicular
