Fungi that cause Piedra.Fungi that cause Piedra.

PiadraPiadra is an infection of scalp hair caused is an infection of scalp hair caused by piedraia hortae and Trichosporon by piedraia hortae and Trichosporon beigelii. beigelii.

Colonization of hair shaft characterized by Colonization of hair shaft characterized by superficial nodules.superficial nodules.

No hair damageNo hair damageBlack piedra and white piedraBlack piedra and white piedra

Black piedraBlack piedra

Piedraia hortaePiedraia hortae, the etiologic agent of black , the etiologic agent of black piedra.piedra.

Found in tropical South and Central American, Found in tropical South and Central American, Southeast Asia, and Africa. Southeast Asia, and Africa.

Fungal colonization of the scalp hair.Fungal colonization of the scalp hair. Hairs with visible nodules should be plucked, Hairs with visible nodules should be plucked,

treated with KOH and examined under the treated with KOH and examined under the microscope. microscope.

The nodule should be crushed, taking care not The nodule should be crushed, taking care not to break the coverslip. to break the coverslip.

The finding of septate brown hyphae, asci, and The finding of septate brown hyphae, asci, and fusiform ascosporesfusiform ascospores

Clinical findingsClinical findings::

Discrete, hard, dark brown to black nodules Discrete, hard, dark brown to black nodules on the hair, which are on the hair, which are small brown-black small brown-black nodules formed on the hair surfaces nodules formed on the hair surfaces consisting of dark colored thick hyphae.consisting of dark colored thick hyphae.

Microscopic examinationMicroscopic examination::A diagnosis can be made by examining a A diagnosis can be made by examining a

potassium hydroxide preparation of a potassium hydroxide preparation of a crushed nodule from an infected hair.crushed nodule from an infected hair.

Nodules are black, hard, and small. Nodules are black, hard, and small. When crushed, the dark colored, branching, When crushed, the dark colored, branching,

thick (4-8 µm) septatethick (4-8 µm) septate pigmented pigmented hyphae hyphae can be seen, usually with large oval asci , can be seen, usually with large oval asci , and ascospores (sexual spores).and ascospores (sexual spores).

CultureCulture::

Cultural techniques are not usually required to Cultural techniques are not usually required to diagnose Piedra, but only in the case of diagnose Piedra, but only in the case of confirming the diagnosis confirming the diagnosis

If done, should be on media with antibacterial If done, should be on media with antibacterial agents, as well as media with both antibacterial agents, as well as media with both antibacterial agents and cycloheximide.agents and cycloheximide.

If it performed, will giveIf it performed, will give: : Brown to black coloniesBrown to black colonies

White piedraWhite piedra

Fungal colonization ofFungal colonization of the coarse hairs of the the coarse hairs of the body body facial, axillary or genital hairfacial, axillary or genital hair

The etiological agent is Trichosporon species The etiological agent is Trichosporon species (yeast(yeast-like organisms that form true-like organisms that form true hyphae, hyphae, arthroconidia, and blastoconidia.arthroconidia, and blastoconidia.))

Different species infect different locations.Different species infect different locations.

T. beigelii (White Piedra), unlike P. hortae, is T. beigelii (White Piedra), unlike P. hortae, is not dark colored. not dark colored.

White nodules are formed consisting of mases White nodules are formed consisting of mases of non pigmented hyphae. of non pigmented hyphae.

Frequent in tropical and temperate zones,Frequent in tropical and temperate zones, South America and parts of Africa and South America and parts of Africa and southern Asia, and other countries.southern Asia, and other countries.

Clinical findingsClinical findings : :

Soft, white to yellowish nodules loosely Soft, white to yellowish nodules loosely attached to the hair.attached to the hair.

MicroscopicMicroscopic::

Direct microscopicDirect microscopic examination of hair nodules examination of hair nodules revealing theserevealing these characteristics should be characteristics should be sufficient for diagnosis. sufficient for diagnosis.

A diagnosis can be made by examining a A diagnosis can be made by examining a potassium hydroxide preparation of a crushed potassium hydroxide preparation of a crushed nodule from an infected hair.nodule from an infected hair.

Nodules are white or pale brown and soft. Nodules are white or pale brown and soft. When crushed 2-4 µm width When crushed 2-4 µm width Intertwined septate Intertwined septate

hyphae can be seen with arthrospores, hyphae can be seen with arthrospores, Blasto- Blasto- and arthroconidiaand arthroconidia

CultureCulture::

Cultural techniques are not usually Cultural techniques are not usually required to diagnose Piedra, but if it required to diagnose Piedra, but if it performed, will give:performed, will give:

Colonies appear rapidly (1–2Colonies appear rapidly (1–2 days) at days) at 30°C on selective agar containing 30°C on selective agar containing antibacterialantibacterial agents.agents. It will be Soft, creamy It will be Soft, creamy coloniescolonies

Species identificationSpecies identification::

Can be accomplished usingCan be accomplished using commercially commercially available assimilation kits, but shouldavailable assimilation kits, but should be be used in conjunction with morphologic used in conjunction with morphologic criteria (e.g.,criteria (e.g., formation of arthroconidia formation of arthroconidia and blastoconida). and blastoconida).

DiagnosisDiagnosis can be easily confirmed by can be easily confirmed by direct microscopic examinationdirect microscopic examination of KOH of KOH mounted scrapings of involved skinmounted scrapings of involved skin or hair. or hair.

Pityriasis versicolor can be confirmed whenPityriasis versicolor can be confirmed when both both round, budding yeast cells and short fat hyphae round, budding yeast cells and short fat hyphae (“spaghetti and meatballs”) are observed. (“spaghetti and meatballs”) are observed.

Wood’s light examination may reveal bright Wood’s light examination may reveal bright yellow fluorescence.yellow fluorescence.

Fungal culture is not helpful as absolute Fungal culture is not helpful as absolute diagnosis because the organism maydiagnosis because the organism may occur in occur in normal skin.normal skin.

Hair shafts from blackpiedra show masses of Hair shafts from blackpiedra show masses of intertwined pigmented hyphaeintertwined pigmented hyphae and occasional and occasional ascospores. In white piedra, there are masses of ascospores. In white piedra, there are masses of hyphae with numerous septa along with plentiful hyphae with numerous septa along with plentiful blastoconidia and arthroconidia.blastoconidia and arthroconidia.

Subcutaneous MycosisSubcutaneous Mycosis::

These are referred to as mycosis of These are referred to as mycosis of implantation because they are acquired implantation because they are acquired when the pathogen is inoculated through when the pathogen is inoculated through the skin by minor cuts or scratches or by the skin by minor cuts or scratches or by thorn or splinter wounds thorn or splinter wounds

The principal subcutaneous mycoses are:The principal subcutaneous mycoses are:Chromomycosis, caused by Phialophora Chromomycosis, caused by Phialophora

species and Cladosporium carrionii.species and Cladosporium carrionii.Mycetoma, caused by several species of Mycetoma, caused by several species of

fungi and actinomycetes.fungi and actinomycetes.Subcutaneous Zygomycosis, caused by Subcutaneous Zygomycosis, caused by

Basidiobolus or Conidiobolus species.Basidiobolus or Conidiobolus species.Rhinosporidiosis: caused by Rhinosporidiosis: caused by

Rhinosporiduim seeberi.Rhinosporiduim seeberi.