Raffinose Growth: +

Caused by Piedraia hortae

No longer a valid species but rather a complex of at least 19 distinct species.

When infected hairs are removed and placed in 10% to 20% KOH, the nodules may be crushed open to reveal the asci.

- Disarticulation (fragmentation) of the hyphae into athroconidia is seen here.

Budding yeast along with septate, sometimes branched, hyphal elements

Characterized by nodules composed of hyphae and a cement-like substance that attaches it to the hair shaft

Thick-walled rhomboid cells containing ascospores are seen

Cycloheximide growth: +

Inositol Growth: +

Are infections confined to the outermost layer of skin or hair

Nitrate Growth: -

Cycloheximide Growth: +/-

Arabinose Growth: -

Raffinose Growth: -

Laboratory Diagnosis: Shiny, moist, yeastlike colonies that start with a brownish coloration that eventually turns olive to greenish black.

Optical microscopy: Identifying the ascus, round structures, typical of parasitism

M. Furfur appearance?

Arabinose Growth: +

Hortaea werneckii

It forms blastoconidia at the apex of the hyphae

Microscopic examination shows septate hyphal elements and budding cells

Characterized by brown or black macular patches, primarily on the palms

Younger cultures are primarily composed of budding blastoconidia, whereas the older mycelial portion of the colony shows hyphae with blastoconidia in clusters

SAB, 30°C, 72 hours

37°C Growth

Optical microscopy: Black Piedra

Urease: +

It also known as wood's lamp or yellow florescence?

Dark nodule attach to the pillar shaft

Inositol Growth: -

Colonies are straw to cream-colored and yeastlike

Culture mycosel medium with dematiaceous colony.

Almost always caused by Hortaea werneckii

Colonies are varied and can be smooth or wrinkled, dry or moist, creamy or velvety in appearance.

Have been implicated in superficial mycoses.

4 to 8um budding of yeasts

Off-white, soft cream-like texture

Skin scrapings - KOH

Disarticulation (fragmentation) of the hyphae into athroconidia is seen here

Old names: Phaeoannellomyces werneckii and Exophiala werneckii

Discoloration or depigmentation and scaling of the skin and is caused by the yeast Malassezia furfur complex.

Caused by Trichophyton ovoides and T. inkin

The direct smear in KOH preparations reveals budding yeasts, approximately 4 to 8 μm, along with septate, sometimes branched, hyphal elements.

Malassezia furfur examination of the direct smear

Grows slowly on Sabouraud dextrose agar at room temperature. It forms brown colonies