SUPERICIAL FUNGI Flashcards
among the most prevalent infectious disease
SUPERFICIAL FUNGI
mode of transmission :
person to person contact (garments, blankets, clothing)
hair infection with nodular masses of fungal elements surrounding the shaft
PIEDRA
infections of the skin
TINEA
macular pathches that are non-scaly
TINEA
Yeast
Malassezia furfur
Trichosporon beigelii
Mold
Piedra hortae
Exophiala werneckii
Exophiala werneckii other name
Phaeoannellomyces werneckii
Tinea versicolor/Pityriasis versicolor, Seborrhoeic dermatitis
Malassezia furfur
- causes dandruff
Seborrhoeic dermatitis
Discoloration on the upper chest, back arms and neck
Malassezia furfur
Hypo/hyper pigmentation
Malassezia furfur
Lesions are well-demarcated
Malassezia furfur
brownish , scaly areas on light skin individuals
lightish , on dark skin individuals
Malassezia furfur
Fawn-colored macules
Malassezia furfur
most common presentation; trunk and upper arms
Fawn-colored macules
Wood’s Lamp Positive (light green flourescence)
Malassezia furfur
skin scrapings, indwelling catheter tips, blood
Malassezia furfur
– common in infants
indwelling catheter tips
Sabouraud’s Dextrose Agar or Sheep Blood Agar containing Acti-Dione
Malassezia furfur
Dixon’s Agar containing glycerol mono-oleate
Malassezia furfur
stimulates growth by natural oil or fatty substances
Malassezia furfur
culture media ; need an addition of oil
Malassezia furfur
1-2 weeks: bacteria-like
Malassezia furfur
Pasty white
Malassezia furfur
the collarettes of the phialides appear as distinct dark rings separation the mother and daughter cells
Malassezia furfur
10% KOH (glycerol w/ Parker ink or Calcofluor white)
Malassezia furfur
PAS/LCPB
Malassezia furfur
Electron Micrograph
Malassezia furfur
Under KOH – cluster of thick walled round budding yeast
Malassezia furfur
Short angular hyphal forms
Malassezia furfur
Topical Agent (imidazole, ketoconazole)
Malassezia furfur
Oral Tx
Malassezia furfur
Tinea nigra
Exophiala werneckii
- chronic superficial fungal on palms
Tinea nigra
Predisposing factor:
excessive sweating
Age:
less than 20 yrs old female
Brown to black macules
Exophiala werneckii
(palmar and plantar and other surfaces of the skin)
Exophiala werneckii
skin scrapings
Exophiala werneckii
SDA – serves as primary isolation media.
Exophiala werneckii
: mucoid like colonies, yeast like , and shiny black appearance
young yeast
: velvety
mature, mold
Dematiaceous: pigment brown to dark
Exophiala werneckii
initially colonies are mucoid, yeastlike and shiny black
Exophiala werneckii
Abundant aerial mycelia and become velvety, dark olivaceous in colour
Exophiala werneckii
2-celled
Exophiala werneckii
– spores
Annelloconidia
– conidiophore
Annellophores
after 7 days
growth of colony; color: off-white
Exophiala werneckii
after 2 -3 weeks o color: olive black
Exophiala werneckii
10% KOH and Parker ink
Calcofluor White Mounts
Exophiala werneckii
Sulfur Soap, SSA (sulfosalicylic), Azoles, Tropical Treatment
Exophiala werneckii
- ascomycetous fungus: produces
pores
Piedra hortae
- Common in central and south america and south east asia
Piedra hortae
: produces pores
ascomycetous fungus
o chronic fungal infection of
the hair shaft
Black Piedra
o mostly affects young adults o epidemics in families
Black Piedra
does not penetrate the hair follicle
Piedra hortae
: rough or sandy
Scalp hair
: black, hard, nodules
on the shaft
Infected hairs
Nodules : hard fusiform
Piedra hortae
: fungal cells cemented
together
Thick part
: hyphal elements
Thin part
hairs with hard black nodules
Piedra hortae
o colonies are dark, brown-
black
Piedra hortae
o take about 2-3 weeks to
appear
Piedra hortae
spore: barrel shape arthroconidia
Piedra hortae
hyphae: thick walled septate
Piedra hortae
- 10 days
Piedra hortae
- Glabrous/ cerebriform
Piedra hortae
: greenish to black
with black reverse
Mature colonies
10% KOH w/ Parker ink; Calcofluor
white
Piedra hortae
Nodules: pigmented center
containing asci
Piedra hortae
- Spore/condia
Piedra hortae
- Hypahe
Piedra hortae
shave or cut the hairs short, terbinafine
Piedra hortae
: 250 mg/per day for 6 weeks
Terbinafine
- Grows at 370C
Trichosporon beigelii
- Sensitive to cycloheximide
Trichosporon beigelii
o superficial cosmetic fungal
infection of the hair shaft
White Piedra
o affects scalp, axilla, facial
and genital hair
White Piedra
- common in young adults
Trichosporon beigelii
- irregular, soft, white or light brown
nodules firmly adhering to the hairs
Trichosporon beigelii
- soft white nodules
Trichosporon beigelii
o white or yellowish to deep
cream colored
Trichosporon beigelii
o smooth, wrinkled, velvety,
dull colonies with a
mycelial fringe
Trichosporon beigelii
- Spore : sympodial blastoconidia – an arthroconidia with pseudohyphae
Trichosporon beigelii
- Hyphae : Hyaline septate
Trichosporon beigelii
- 5 days
Trichosporon beigelii
- Cream and waxy
Trichosporon beigelii
- Spore
- Hyphae
Trichosporon beigelii
shave the hairs, tropical
Trichosporon beigelii
Tinea Versicolor
Malassezia furfur
Yeast
Malassezia furfur
Trichosporon beigelii
Mould
Exophiala werneckii (Phaeoannellomyces werneckii)
Piedra horta
Skin (chest, arms, back)
Malassezia furfur
Temperate
Malassezia furfur
Trichosporon beigelii
Hypopigmented
Malassezia furfur
Requires Fatty Acids
Malassezia furfur
Spaghetti and meatballs (PAS), bowling pins (electromicrograph), medicine capsule
Malassezia furfur
Tinea Nigra
Exophiala werneckii (Phaeoannellomyces werneckii)
Skin (hands, feet)
Exophiala werneckii (Phaeoannellomyces werneckii)
Tropical
Exophiala werneckii (Phaeoannellomyces werneckii)
Piedra horta
Dark, Macular
Exophiala werneckii (Phaeoannellomyces werneckii)
Slow growth
Exophiala werneckii (Phaeoannellomyces werneckii)
Anneloconidia
Exophiala werneckii (Phaeoannellomyces werneckii)
Black Piedra
Piedra horta
Hair (scalp, eyebrows, eyelashes, pubic hair)
Piedra horta
Black, hard
Piedra horta
Barrel-shaped arthroconidia
Piedra horta
White Piedra
Trichosporon beigelii
Hair (mustache, beard, axillary, groin)
Trichosporon beigelii
White, soft
Trichosporon beigelii
Sympodial blastoconidia
Trichosporon beigelii