SUPERFICIAL MYCOSES Assoc.Prof.Dr.Yesim Gürol

Learning Objectives To list dermatophytes To list subcutaneous mycoses

infections caused by dermatophytic fungi (dermatophytosis) Nondermatophytic fungi (dermatomycosis)

DERMATOPHYTOSES Trichophyton Epidermophyton Microsporum cause disease in animals and/or humans. have the ability to invade the skin,hair or nails. keratinophylic and keratinolytic. invade upper outermost layer of epidermis

dermatophytosis tineas ringworm

Morphology and Identification identified by colonial appearance microscopic morphology Growth at Sabouraud’s dextrose agar at 25oC for two weeks

Epidermophyton floccosum Microsporum canis Microsporum audouinii

Microsporum persicolor

Trichophyton spp.

Epidemiology and immunity Begins in the skin after trauma and contact Host susceptibility depends on Moisture Warmth Spesific skin chemistry Composition of sebum and perspiration Youth Heavy exposure Genetic predisposition

Dermatophytes are classified as anthropophilic, zoophilic or geophilic according to their normal habitat. Anthropophilic human hosts mild, chronic inflammation. Zoophilic primarily in animals inflammatory reactions in humans who have contact with infected cats, dogs, cattle, horses, birds, or other animals. followed by a rapid termination of the infection Geophilic from the soil occasionally infect humans and animals. They cause a marked inflammatory reaction, which limits the spread of the infection and may lead to a spontaneous cure but may also leave scars.

Contagious Frequently transmitted by exposure to shed skin scales, nails or hair containinh hyphae or conidia

Tinea capitis Tinea favosa Tinea corporis Tinea pedis Tinea manuum Tinea imbricata Tinea cruris Tinea barbae Tinea nigra Tinea ungium

Tinea capitis infection of the scalp with a dermatophyte fungus. Hair can be infected with Trichophyton (abbreviated as "T".) and Microsporum ("M".) fungi. classified according to how the fungus invades the hair shaft: Ectothrix infection The fungal branches (hyphae) and spores (arthroconidia) cover the outside of the hair. Ectothrix infections can be identified by Woods light (long wave ultraviolet light) examination of the affected area the vet uses this to check your cats fur. Endothrix infection The hair shaft is filled with fungal branches (hyphae) and spores (arthroconidia). Endothrix infections do not fluoresce with Woods light. Favus caused by T. schoenleinii infection honeycomb destruction of the hair shaft

macroconidia

When the hair is infected, ectothrix endothrix favic

Tinea capitis may present in several ways. Dry scaling – like dandruff but usually with moth-eaten hair loss Black dots – the hairs are broken off at the scalp surface, which is scaly Smooth areas of hair loss Kerion – very inflamed mass, like an abscess Favus – yellow crusts and matted hair Carrier state no symptoms and only mild scaling

Trichophytid reaction (id reaction) The patient may become hypersensitive to constituents or products of the fungus and develop allergic manifestations Usually vesicles Mostly on the hands No fungi present in lesion

Tinea capitis

Tinea capitis caused by Trichophyton mentagrophytes

Tinea barbae

Tinea pedis (Athlete’s foot)

Tinea corporis

Tinea unguium (onychomycosis) Tinea ingualis (cruris) (jock itch)

SUBCUTANEOUS MYCOSES Normally reside in soil or vegetation Enter the skin or subcutaneous tissue by traumatic inoculation with contaminated material Sporotrichosis Chromoblastomycosis Eumycotic mycetoma Subcutaneous zygomycosis Subcutaneous phaeohyphomycosis

SPOROTRICHOSIS Sporothrix schenkii Thermally dimorphic Usually sporadic Most common in warmer climates Outbreaks related to forest work, mining, gardening Classic infection traumatic inoculation of soil or vegetable or organic matter contaminated with fungus Zoonotic transmission with armadillo hunters and infected cats

Chronic infection Nodular and ulcerative lesions that develop along lymphatics grossly may resemble a malignant process ‘squamous cell carcinoma’ Dissemination to other sites rare !(bones,eyes,lungs, central nervous system)

Specimens: Biopsy Exudate from lesions Culture

S.schenckii

Chromoblastomycosis (chromomycosis) chronic fungal infection slow growing verrucous nodules or plaques mostly in tropics Pigmented fungi (dematiaceous fungi) Fonsecaea Cladosporium Exophiala Cladophialophora Rhinocladiella Phialophora

into the skin by trauma Verrucous, wart like lesions Cauliflower like nodules Rarely elephanthiasis

Subcutaneous phaeohyphomycosis Darkly pigmented septate hyphae in tissue Cutaneous and systemic infections Solitary encapsulated cysts in the subcutaneous tissue Sinusitis Brain abscesses (usually fatal) All exogenous molds that normally exist in nature

phaeohyphomycosis Exophiala, Phialophora, Wangiella, Bipolaris, Exserohilum, Cladophialophora , Phaeoannellomyces, Aureobasidium, Cladosporium, Curvularia Alternaria

MYCETOMA Local swelling of infected tissue and interconnecting Often draining Sinuses or fistulae that contain granules Actinomycetoma....mycetoma caused by an actinomycete Eumycetoma....(Madura foot, maduromycosis) mycetoma caused by a fungus Clinical features similar Treatment different Actinomycetomas more invasive

MYCETOMA

After traumatic inoculation with soil contaminated with one of these agents Feet, lower extremities, hands and exposed areas Suppuration, abscesses, granules, Contagious muscle and bone Deformation, loss of function Very rarely foreign body (e.g.cardiac pacemaker) infection