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Skin and soft tissues infections. Classification of mycoses. Superficial and cutaneous Subcutaneous Deep (systemic) . Superficial mycoses . Caused by fungi living as saprophytes Hair, dead skin and lipids secretions They don’t provoke any immune response No pain or itching.
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Classification of mycoses • Superficial and cutaneous • Subcutaneous • Deep (systemic)
Superficial mycoses • Caused by fungi living as saprophytes • Hair, dead skin and lipids secretions • They don’t provoke any immune response • No pain or itching
Pityriasisversicolor • Common, mild and chronic infection of stratum corneum • World-wide • More common in tropics and sub-tropics • In temperate regions more common during summer
PityriasisversicolorCaused by Malasseziayeast, which is lipophilic dimorphic fungus
Tineanigra Typical brown to black, non-scaling macules on the palmar aspect of the hands. Note: there is no inflammatory reaction
Cutaneous mycoses • Infections in the living parts of the body: • Skin • Hair and nail • Mucocutaneous membranes • Genitalia • Tow types can be recognized • Dematophytes infections • Non-dermatophytes infections
Dematophytes infections(dematophytosis) • Ringworm (hair and skin) • Favus (hair) • Onychomycosis (nail)
Dermatophytosis(=Tinea = Ringworm) Infections of the skin, hair and nails due to a group of related filamentous keratinophilic fungi called dermatophytes
Dermatophytes • Microsporum Hair, skin • Epidermophyton Skin, nail • Trichophyton Hair, skin, nail • Digest keratin by their keratinases • Resistant to cycloheximide
Epidemiology and natural habitat • Some have a world-wide distribution • Some are restricted to particular regions • About 10 species are common causes of human infection • Classified into three groups depending on their usual habitat
Anthropophilic • Human is usual host • T. rubrum (foot & nail infections) • E. floccosum (foot & nail infections) • T. tonsurans (scalp infections) • M. audouinii (scalp infections)
Geophilic • Normal habitat is soil • Can cause infections in both humans and animals • Microsporumgypseum
Zoophilic • Often associated with a particular animal • Microsporumcanis: cats and dogs • Trichophytonverrucosum: horse and cattle
Dermatophytosis • Skin: • Circular dry lesions • Slightly raised red scaly margins • Surrounded by red itchy skin • Fungus remain restricted to stratum corneum • Metabolites provoke inflammation • Hair: • Typical lesions → scarring + alopecia • Nail: • Thickened, deformed, fragile, discolored • Sub-ungual debris accumulation
Dermatophytosis clinical classification Infection is named according to the anatomic location involved
Clinical manifestation (1) • Ringworm • Tineapedis (athlete's foot) • Tineamanuum (hands) • Tineacorporis (trunk, neck and back) • Tineacruris (hairy skin around the genitilia) • Tineabarbae (hairy skin in the face) • Tineacapitis (scalp and eyebrows)
Clinical manifestation (2) • Favus (scalp) • Onychomycosis (nail)
Tinea corporis Tinea corporis caused by M. canisfollowing contact with infectious cat
Tineacruris Tinea of the groin showing typical erythematous lesions on the inner thighs Tinea of the buttocks
Tinea capitis caused by M. canisfollowing contact with infectious cat Tinea capitis showing extensive hair losscaused by M. canis
Favus and Onychomycosis • Favus • Special form of tineacapitis • Onychomycosis • Fungal infection of nail • The term "tineaunguium" is used specifically to describe dermatophyticonychomycosis
Laboratory diagnosis • 50 % of suspicious materials may be negative • Hyphae and/or arthrospores is diagnostic • Culture is more reliable: • Determined species • Source of infection • Can be positive even if direct examination is negative
Management • Dependant on the clinical setting • Topical or oral antifungal
Non-dermatophytescutaneous infections • Onychmycosis • Intertrigo • Mucocutaneouscandidiasis • Thrush • Vulvo-vaginitis
Intertrigo caused by Candida albicans
Red macerated rash under pendulous breasts is a common presentation of cutaneous candidiasis
Candida diaper dermatitis This condition should not be considered a primary Candida infection as it preceded by an irritant dermatitis
Subcutaneous Mycoses • Skin, subcutaneous tissues, fascia and bone • Localized • Trauma • More in tropics • Mycetoma, chromomycosis and sporotrichosis
Sporotrichosis A 60-year-old woman developed multiple subcutaneous nodules and abscesses on her right hand and forearm 7 days after finger thorn prick
Classical Chromoblastomycosis: Fonsecaea pedrosoi De Hoog,Centraalbureau voor Schimmelcultures
Nodulose chromoblastomycosis (Senegal): Fonsecaea pedrosoi De Hoog,Centraalbureau voor Schimmelcultures
Management • Difficult • Surgical excision • Itraconazole and other antifungal