FUNGAL DISEASES of THE FUNGAL DISEASES of THE SKINSKIN

DR. ZIAD ELNASSERDR. ZIAD ELNASSER

FUNGIFUNGIMore than 200,000 species.More than 200,000 species.Eucaryotes.Eucaryotes.Chronic diseases.Chronic diseases.

STRUCTURESTRUCTURE

No peptidoglycan, glycerol, LPS, or No peptidoglycan, glycerol, LPS, or teichoic acids.teichoic acids.

Cell wall is formed of Polysaccharides, Cell wall is formed of Polysaccharides, Mannan, Glucan, and Chitin.Mannan, Glucan, and Chitin.

Determinants of serologic specificity.Determinants of serologic specificity.Chitin is similar to crab shells or cellulose Chitin is similar to crab shells or cellulose

of plansts.of plansts.

METABOLISMMETABOLISM

Heterotrophic, decaying organic matter.Heterotrophic, decaying organic matter.Strict aerobes, some are anaerobes.Strict aerobes, some are anaerobes.Asexual vs Sexual reproduction, Asexual vs Sexual reproduction,

Conidia vs Spores.Conidia vs Spores.

GROWTH AND MORPHOLOGYGROWTH AND MORPHOLOGY

Size 2 - 4 µ up to visible structures.Size 2 - 4 µ up to visible structures.Two courses Two courses YEASTYEAST and or and or MOLD.MOLD.Yeasts buds produce blastoconidia.Yeasts buds produce blastoconidia.Colonies.Colonies.Molds formMolds form Hyphae Hyphae then then MyceliumMycelium, ,

SeptaSepta..Aerial, or Rhizoids.Aerial, or Rhizoids.Pseudohyphae.Pseudohyphae.

GROWTH AND MORPHOLOGYGROWTH AND MORPHOLOGY

Conidia on a condiophore.Conidia on a condiophore.Macroconidia, Microconidia.Macroconidia, Microconidia.Chlamydoconidia.Chlamydoconidia.ArthroconidiaArthroconidiaAscosporesAscospores

DimorphicDimorphic fungi. fungi.

CLASSIFICATIONCLASSIFICATION

Depends on spores, septation.Depends on spores, septation.Zygomycetes.Zygomycetes.Ascomycetes.Ascomycetes.Basidiomycetes.Basidiomycetes.Deuteromycetes Deuteromycetes (Fungi imperfecta).(Fungi imperfecta).

CLASSIFICATIONCLASSIFICATION

Superficial Mycosis.Superficial Mycosis.Subcutaneous Mycosis.Subcutaneous Mycosis.Opportunistic Fungi.Opportunistic Fungi.Systemic Mycosis.Systemic Mycosis.

SUPERFICIAL MYCOSISSUPERFICIAL MYCOSIS

Dermatophytes.Dermatophytes.Tinea versicolor.Tinea versicolor.Tinea nigra.Tinea nigra.Piedra.Piedra.

DERMATOPHYTESDERMATOPHYTES

Ring worm, Tinea, Atheletes foot, Jock itch.Ring worm, Tinea, Atheletes foot, Jock itch. Epidermophyton, Microsporum, Trichophyton.Epidermophyton, Microsporum, Trichophyton. Macroconidia morphology.Macroconidia morphology. Grows on SAB, 25 C, septate hyphae.Grows on SAB, 25 C, septate hyphae.

EPIDEMIOLOGYEPIDEMIOLOGY

Adapted to skin of humans and or animals.Adapted to skin of humans and or animals. Soil.Soil. Low infectivity, close contact.Low infectivity, close contact. Families, barber shops, locker rooms.Families, barber shops, locker rooms. Simple hands washing.Simple hands washing.

PATHOGENESISPATHOGENESIS

Minor trauma, stratum corneum not Minor trauma, stratum corneum not deeper.deeper.

Anatomic location, skin growth and Anatomic location, skin growth and desquamation, inflamatory response.desquamation, inflamatory response.

Role of CorticosteroidsRole of Corticosteroids..Ring worms or Tineas.Ring worms or Tineas.Skin, nails, hair (exothrix, endothrix).Skin, nails, hair (exothrix, endothrix).

IMMUNITYIMMUNITY

Inflamatory stage to complete healing.Inflamatory stage to complete healing.Antibodies play no role.Antibodies play no role.CMI and DH play a mojor role.CMI and DH play a mojor role.Enhanced desquamation.Enhanced desquamation.Conditions affecting T cell function.Conditions affecting T cell function.Some grow with no inflammation?Some grow with no inflammation?

CLINICAL MANIFESTAIONSCLINICAL MANIFESTAIONS

In apparent to chronic.In apparent to chronic. Tinea capitis (Scalp), Itching, hair dots.Tinea capitis (Scalp), Itching, hair dots. Tinea pedis (Foot), Itching, moist, sweatyTinea pedis (Foot), Itching, moist, sweaty Tinea mannuum (Hands)Tinea mannuum (Hands) Tinea cruris (Groin), obesity.Tinea cruris (Groin), obesity. Tinea barbae (beared)Tinea barbae (beared) Tinea ungium (Nail bed), discoloration.Tinea ungium (Nail bed), discoloration. Tinea corporis (body), itching.Tinea corporis (body), itching.

DIAGNOSISDIAGNOSIS

Differentiate from other illnesses.Differentiate from other illnesses.Microscopy, skin scaping.Microscopy, skin scaping.Woods lamp.Woods lamp.CultureCulture? In negative cases only.? In negative cases only.

TREATMENTTREATMENT

Many are self limiting.Many are self limiting.Tolnaftate.Tolnaftate.Naftifine.Naftifine.Azoles.Azoles.Grisiofulvin or Ketoconazole (systemic)Grisiofulvin or Ketoconazole (systemic)Keratolytic agents.Keratolytic agents.General preventive measures.General preventive measures.

Tinea versicolorTinea versicolor

Pityriasis versicolor(Pityrosporum Pityriasis versicolor(Pityrosporum orbiculare).orbiculare).

Discrete hypopigmentation, induration, and Discrete hypopigmentation, induration, and scaling.scaling.

Trunk, arms.Trunk, arms. Pigmentaion varies form pink to brown.Pigmentaion varies form pink to brown. Skin scaping shows budding yeast with Skin scaping shows budding yeast with

hyphae.hyphae.

Tinea nigraTinea nigra

Tropical.Tropical.Brown to black macular lesions.Brown to black macular lesions.Little inflamation, no scaling.Little inflamation, no scaling.Cladosporum werneckiiCladosporum werneckii..Brown to black pigmented septate hyphae.Brown to black pigmented septate hyphae.Yeast form slow hyphal forms.Yeast form slow hyphal forms.

PiedraPiedra

Hair only.Hair only.Black or white nodules.Black or white nodules.White (Trichosporum cutaneum)White (Trichosporum cutaneum)Black (Piedra hortae)Black (Piedra hortae)

SUBCUTANEOUS MYCOSISSUBCUTANEOUS MYCOSIS

Sporotrichosis, single agent.Sporotrichosis, single agent.Chromoblastomycosis, multiple.Chromoblastomycosis, multiple.Mycetoma, multiple.Mycetoma, multiple.Trauma, localized under the skin.Trauma, localized under the skin.

SPOROTRICHOSISSPOROTRICHOSIS

Sporothrix schenckiiSporothrix schenckii.. Dimorphic.Dimorphic. Cigar shaped yeast.Cigar shaped yeast. Septate hyphae, cluster of conidia on a phore.Septate hyphae, cluster of conidia on a phore. Found in soil, Thorn brick injury.Found in soil, Thorn brick injury.

PATHOGENESISPATHOGENESIS

Acute pyogenic and granulomatous Acute pyogenic and granulomatous reactionreaction

Painless papule, enlarges then ulcerates.Painless papule, enlarges then ulcerates.Enlarged L.Ns, chronic course.Enlarged L.Ns, chronic course.Systemic involvement rare.Systemic involvement rare.

DIAGNOSISDIAGNOSIS

Microscopy is not effective.Microscopy is not effective.Biobsy usually negative, but if positive Biobsy usually negative, but if positive

asteroid body is diagnostic.asteroid body is diagnostic.Definitive Dx is by culture.Definitive Dx is by culture.

TREATMENTTREATMENT

Potassium iodid.Potassium iodid.Amphotericin B.Amphotericin B. Itraconazole.Itraconazole.

CHROMOBLASTOMYCOSISCHROMOBLASTOMYCOSIS

PhialophoraPhialophora and and CladosporiumCladosporium..Tropical, on foot or leg.Tropical, on foot or leg.Papule then warty like structure.Papule then warty like structure.Painless, no L.Ns involvement.Painless, no L.Ns involvement.Soil, bare footed people.Soil, bare footed people.Brown pigmented hyphae.Brown pigmented hyphae.Surgery, Flucytosine.Surgery, Flucytosine.

MYCETOMAMYCETOMA

Trauma to the foot.Trauma to the foot. Multiple agents.Multiple agents. Petrieldium boydiiPetrieldium boydii.. Massive induration with sinusis.Massive induration with sinusis. Tropical environment.Tropical environment. Morphology of the sexual microconidia.Morphology of the sexual microconidia. Nocarida causes the same disease.Nocarida causes the same disease. Difficult to treatDifficult to treat