SUPERFICIAL MYCOSES Sevtap Arikan, MD

SUPERFICIAL MYCOSES bDermatophytosis bPityriasis versicolor bKeratomycosis bTinea nigra bBlack piedra bWhite piedra

DERMATOPHYTOSIS (=Tinea = Ringworm) b Infection of the skin, hair or nails caused by a group of keratinophilic fungi, called dermatophytes ¨ Microsporum Hair, skin ¨ EpidermophytonSkin, nail ¨ TrichophytonHair, skin, nail

DERMATOPHYTES b Digest keratin by their keratinases b Resistant to cycloheximide b Classified into three groups depending on their usual habitat

DERMATOPHYTES b ANTROPOPHILIC Trichophyton rubrum... Trichophyton rubrum... b GEOPHILIC Microsporum gypseum... b ZOOPHILIC Microsporum canis: cats and dogs Microsporum nanum: swine Trichophyton verrucosum: horse and swine…

DERMATOPHYTOSIS Pathogenesis and Immunity b Contact and trauma b Moisture b Crowded living conditions b Cellular immunodeficiency  (chronic inf.) b Re-infection is possible (but, larger inoculum is needed, the course is shorter )

DERMATOPHYTOSIS Clinical Classification b Infection is named according to the anatomic location involved: a. Tinea barbaee. Tinea pedis (Athlete’s foot) b. Tinea corporis f. Tinea manuum c. Tinea capitis g. Tinea unguium d. Tinea cruris (Jock itch)

DERMATOPHYTOSIS Clinical manifestations b Skin: Circular, dry, erythematous, scaly, itchy lesions b Hair: Typical lesions,”kerion”, scarring, “alopecia” b Nail: Thickened, deformed, friable, discolored nails, subungual debris accumulation b Favus (Tinea favosa)

DERMATOPHYTOSIS Transmission b Close human contact b Sharing clothes, combs, brushes, towels, bedsheets... (Indirect) b Animal-to-human contact (Zoophilic)

DERMATOPHYTOSIS Diagnosis I. Clinical Appearance Wood lamp (UV, 365 nm) II. Lab A. Direct microscopic examination (10-25% KOH) Ectothrix/endothrix/favic hair

DERMATOPHYTOSIS Diagnosis B. Culture Mycobiotic agar Sabouraud dextrose agar

DERMATOPHYTES Identification A. Colony characteristics B. Microscopic morphology MacroconidiumMicroconidium Microsporum----fusiform (+) Epidermophytonclavate (-) Trichophyton-- -(few)cylindrical/ (+) clavate/fusiform single, in clusters

DERMATOPHYTES Identification C. Physiological tests b In vitro hair perforation test b Special amino acid and vitamin requirements b Urea hydrolysis b Growth on BCP-milk solids-glucose medium b Growth on polished rice grains b Temperature tolerance and enhancement

DERMATOPHYTOSIS Treatment b Topical Miconazole, clotrimazole, econazole, terbinafine... b Oral GriseofulvinKetaconazoleItraconazoleTerbinafine

PITYRIASIS VERSICOLOR b Superficial chronic infection of Stratum corneum b Etio: Malassezia furfur (Pityrosporum orbiculare) (Lipophilic yeast) b Clinical findings: Hyperpigmented or depigmented maculae on chest, back, arms, abdomen

PITYRIASIS VERSICOLOR b Systemic infection (parenteral lipid solution) b Micr.: Short hyphae, yeast cells b Culture: Yeast (suppl.: olive oil) b Treatm.: Topical selenium sulfide Oral ketaconazole Oral itraconazole Oral itraconazole

KERATOMYCOSIS (=Mycotic keratitis) b Posttraumatic / postsurgical corneal inf. b Etio: Saprophytic fungi (Aspergillus, Fusarium, Alternaria, Candida), Histoplasma capsulatum b Clinical findings: Corneal ulcer

KERATOMYCOSIS  Micr.: Hyphae in corneal scrapings b Treatm.: Surgery (keratoplasty) Topical pimaricin Topical pimaricin Nystatin Nystatin Amphotericin B Amphotericin B

TINEA NIGRA b Superficial chronic infection of Stratum corneum b Etio: Hortae (Exophiala) werneckii (pigmented) b Frequent in tropical areas b Clinical findings: Brownish maculae on palms, fingers, face

TINEA NIGRA b Micr.:Septate hyphae and yeast cells (brown in color) b Culture: Black colonies b Treatm.: Topical salicylic acid, tincture of iodine

BLACK PIEDRA b Fungal infection of the scalp hair b Etio: Piedraia hortae b Frequent in tropical areas b Clinical findings: Discrete, hard, dark brown to black nodules on the hair

BLACK PIEDRA b Micr. Septate pigmented hyphae, and asci; unicellular and fusiform ascospores with polar filament(s) b Culture: Brown to black colonies b Treatm.: Topical salicylic acid, azol cremes

WHITE PIEDRA b Fungal infection of facial, axillary or genital hair b Etio: Trichosporon (yeast) b Frequent in tropical and temperate zones

WHITE PIEDRA b Clinical findings: Soft, white to yellowish nodules loosely attached to the hair b Micr.: Intertwined septate hyphae, blasto- and arthroconidia b Culture: Soft, creamy colonies b Treatm.: Shaving, azoles