Superficial Mycoses Superficial Mycoses (Dermatophytes)(Dermatophytes)

((Skin PlantsSkin Plants))

SUPERFICIAL MYCOSESSUPERFICIAL MYCOSESThe superficial mycoses are usually confined The superficial mycoses are usually confined

to the outermost layer of skin, hair and do to the outermost layer of skin, hair and do not invade living tissues. not invade living tissues.

Cutaneous mycosesCutaneous mycoses

Infection of the skin, hair or nails Infection of the skin, hair or nails caused by a group of keratinophilic caused by a group of keratinophilic fungi, called dermatophytesfungi, called dermatophytes

DERMATOPHYTOSISDERMATOPHYTOSIS(=Tinea = Ringworm)(=Tinea = Ringworm)

Tinea means "ringworm" or "moth-like". Dermatologists use the term to refer to a variety of lesions of the skin or scalp.

extend deeper into the epidermis, as well as invasive hair and nail diseases.

DERMATOPHYTESDERMATOPHYTES Digest keratin by their Digest keratin by their

keratinaseskeratinases Resistant to cycloheximideResistant to cycloheximide Classified into Classified into three groupsthree groups

depending on their usual habitatdepending on their usual habitat

DermatophytesDermatophytes3 Genera3 Genera

TrichophytonTrichophyton MicrosporumMicrosporum EpidermophytonEpidermophyton

DERMATOPHYTOSISDERMATOPHYTOSISClinical Classification & Clinical Classification &

ManifestationsManifestations Infection is named according to the Infection is named according to the

anatomic location involved:anatomic location involved:- Tinea corporis - small lesions occurring Tinea corporis - small lesions occurring

anywhere on the bodyanywhere on the body

- Tinea pedis - "athlete's foot". Infection of Tinea pedis - "athlete's foot". Infection of toe webs and soles of feet. toe webs and soles of feet.

- Tinea unguium (onychomycosis) - nails. Tinea unguium (onychomycosis) - nails. Clipped and used for cultureClipped and used for culture

- Tinea capitis - head. Frequently found in Tinea capitis - head. Frequently found in children children

- Tinea barbae - ringworm of the bearded Tinea barbae - ringworm of the bearded areas of the face and neck. areas of the face and neck.

Ecology of DermatophytesEcology of Dermatophytes

To determine the source of To determine the source of infectioninfection

AnthropophilicAnthropophilic ZoophilicZoophilic GeophilicGeophilic

AnthropophilicAnthropophilic

Associated with humans only. Person Associated with humans only. Person -to-person transmission through -to-person transmission through contaminated objects (comb, hat, contaminated objects (comb, hat, etc.)etc.)

ZoophilicZoophilic

Associated with animals. Direct Associated with animals. Direct transmission to humans by close transmission to humans by close contact with animalscontact with animals..

GeophilicGeophilic

Usually found in soil. Usually found in soil. Transmitted to humans by Transmitted to humans by direct exposuredirect exposure..

Trichophyton Trichophyton (19 species)(19 species)

Hair Hair SkinSkin NailsNails

Trichophyton speciesTrichophyton species

Large, smooth, thin wall, septate, pencil-shaped

Trichophyton rubrumTrichophyton rubrum

Causes a chronic infection in Causes a chronic infection in patients with a cell-mediated patients with a cell-mediated immune defect.( Tinea immune defect.( Tinea Capitis).Capitis).

Epidermophyton floccosumEpidermophyton floccosum

SkinSkin NailsNails

Epidermophyton floccosumEpidermophyton floccosum

Bifurcated hyphae with multiple, smooth, club shaped macroconidia )2-4 cells(

MicrosporumMicrosporum(13 species)(13 species)

SkinSkin HairHair

Microsporum speciesMicrosporum species

Thick wall, spindle shape, multicellular

Microsporum canisMicrosporum canis

Most common etiologic agent Most common etiologic agent of tineaof tinea

DERMATOPHYTOSISDERMATOPHYTOSISDiagnosisDiagnosis

I. ClinicalI. ClinicalAppearanceAppearanceWood’s lamp (UV, 365 nm) Wood’s lamp (UV, 365 nm) II. Lab II. Lab A.A. Direct microscopic examination Direct microscopic examination(10-25% KOH)(10-25% KOH)

DERMATOPHYTOSISDERMATOPHYTOSISDiagnosisDiagnosis

B.B. Culture CultureMycobiotic agar Mycobiotic agar Sabouraud dextrose agar Sabouraud dextrose agar

Dermatophytes CultureDermatophytes Culture

Dermatophyte CultureDermatophyte Culture

Black collection card

DERMATOPHYTOSISDERMATOPHYTOSISTreatmentTreatment

Topical Topical Miconazole, clotrimazole, Miconazole, clotrimazole, econazole, terbinafine...econazole, terbinafine...

OralOralGriseofulvinGriseofulvinKetaconazoleKetaconazoleItraconazoleItraconazoleTerbinafineTerbinafine

SUPERFICIAL MYCOSESSUPERFICIAL MYCOSESPityriasis versicolor Pityriasis versicolor Tinea nigraTinea nigraBlack piedraBlack piedraWhite piedraWhite piedraKeratomycosisKeratomycosis

PITYRIASIS VERSICOLORPITYRIASIS VERSICOLOR(Tinea versicolor)(Tinea versicolor)

Superficial chronic infection of Superficial chronic infection of Stratum corneumStratum corneum

Etio: Etio: Malassezia furfur Malassezia furfur (Pityrosporum orbiculare)(Pityrosporum orbiculare) (Lipophilic yeast)(Lipophilic yeast)

Clinical findings: Clinical findings: Hyperpigmented Hyperpigmented or depigmented maculae on or depigmented maculae on chest, back, arms, abdomenchest, back, arms, abdomen

- Characterized by a blotchy discoloration of Characterized by a blotchy discoloration of skin which may itch.skin which may itch.

- Up to 25% of the general population may have this - Up to 25% of the general population may have this lesion at any one time. lesion at any one time.

- Diagnosis is usually possible by direct microscopic - Diagnosis is usually possible by direct microscopic examination of KOH-treated skin scrapings which examination of KOH-treated skin scrapings which show a typical aspect of mycelia and spores show a typical aspect of mycelia and spores described as "spaghetti and meatballs.“described as "spaghetti and meatballs.“

PITYRIASIS PITYRIASIS VERSICOLORVERSICOLOR

Treatm.: Treatm.: Topical selenium Topical selenium sulfidesulfideOral ketaconazoleOral ketaconazole Oral itraconazoleOral itraconazole

TINEA NIGRATINEA NIGRA Superficial chronic infection of Superficial chronic infection of

Stratum corneumStratum corneum Etio: Etio: HortaeHortae (Exophiala) (Exophiala)

werneckii werneckii (pigmented)(pigmented) Frequent in tropical areasFrequent in tropical areas Clinical findings:Clinical findings: Brownish Brownish

maculae on palms, fingers, facemaculae on palms, fingers, face

TINEA NIGRATINEA NIGRA Micr.: Micr.: Septate hyphae and yeast Septate hyphae and yeast

cells (brown in color)cells (brown in color) Culture:Culture: Black colonies Black colonies Treatm.: Treatm.: Topical salicylic acid, Topical salicylic acid,

tincture of iodinetincture of iodine

BLACK PIEDRABLACK PIEDRA Fungal infection of the scalp hairFungal infection of the scalp hair Etio:Etio: Piedraia hortae Piedraia hortae Frequent in tropical areasFrequent in tropical areas Clinical findings: Clinical findings: Discrete, hard, Discrete, hard,

dark brown to black nodules on dark brown to black nodules on the hairthe hair

BLACK PIEDRABLACK PIEDRA

Micr.Micr. Septate pigmented hyphae, Septate pigmented hyphae, and asci; unicellular and fusiform and asci; unicellular and fusiform ascospores with polar filament(s)ascospores with polar filament(s)

Culture:Culture: Brown to black colonies Brown to black colonies Treatm.: Treatm.: Topical salicylic acid, Topical salicylic acid,

azol cremesazol cremes

WHITE PIEDRAWHITE PIEDRA

Fungal infection of facial, Fungal infection of facial, axillary or genital hairaxillary or genital hair

Etio:Etio: Trichosporon Trichosporon (yeast)(yeast) Frequent in tropical and Frequent in tropical and

temperate zonestemperate zones

WHITE PIEDRAWHITE PIEDRA Clinical findings:Clinical findings: Soft, white to Soft, white to

yellowish nodules loosely yellowish nodules loosely attached to the hairattached to the hair

Micr.:Micr.: Intertwined septate Intertwined septate hyphae, blasto- and hyphae, blasto- and arthroconidiaarthroconidia

Culture:Culture: Soft, creamy colonies Soft, creamy colonies Treatm.: Treatm.: Shaving, azolesShaving, azoles

KERATOMYCOSISKERATOMYCOSIS(=Mycotic keratitis)(=Mycotic keratitis)

Posttraumatic / postsurgical Posttraumatic / postsurgical corneal inf. corneal inf.

Etio:Etio: Saprophytic fungi Saprophytic fungi ((AspergillusAspergillus, , Fusarium, Fusarium, Alternaria, Candida), Alternaria, Candida), Histoplasma capsulatumHistoplasma capsulatum

Clinical findings: Clinical findings: Corneal ulcerCorneal ulcer

KERATOMYCOSISKERATOMYCOSIS Micr.:Micr.: Hyphae in corneal Hyphae in corneal

scrapingsscrapings Treatm.:Treatm.: Surgery (keratoplasty)Surgery (keratoplasty)

Topical pimaricinTopical pimaricin NystatinNystatin Amphotericin BAmphotericin B