Are infections confined to the outermost layer of skin or hair

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

Almost always caused by Hortaea werneckii

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

Old names: Phaeoannellomyces werneckii and Exophiala werneckii

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

Caused by Piedraia hortae

Caused by Trichophyton ovoides and T. inkin

Skin scrapings - KOH

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

M. Furfur appearance?

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

Microscopic examination shows septate hyphal elements and budding cells

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

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

Thick-walled rhomboid cells containing ascospores are seen

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

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

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

Have been implicated in superficial mycoses.

Colonies are straw to cream-colored and yeastlike

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

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

Malassezia furfur examination of the direct smear

Budding yeast along with septate, sometimes branched, hyphal elements

4 to 8um budding of yeasts

Hortaea werneckii

Dark nodule attach to the pillar shaft

Culture mycosel medium with dematiaceous colony.

Optical microscopy: Black Piedra

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

37°C Growth

Cycloheximide growth: +

Cycloheximide Growth: +/-

Nitrate Growth: -

Urease: +

Raffinose Growth: +

Raffinose Growth: -

Inositol Growth: +

Inositol Growth: -

Arabinose Growth: +

Arabinose Growth: -

Off-white, soft cream-like texture

SAB, 30°C, 72 hours

It forms blastoconidia at the apex of the hyphae

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