skin and soft tissues infections

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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 dont provoke any immune response No pain or itching. - PowerPoint PPT Presentation

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Skin and soft tissues infectionsClassification of mycosesSuperficial and cutaneous

Subcutaneous

Deep (systemic) Superficial mycoses Caused by fungi living as saprophytesHair, dead skin and lipids secretionsThey dont provoke any immune responseNo pain or itchingPityriasis versicolorCommon, mild and chronic infection of stratum corneumWorld-wideMore common in tropics and sub-tropicsIn temperate regions more common during summer4

Pityriasis versicolor Caused by Malassezia yeast, which is lipophilic dimorphic fungus

KOH Parker ink staining 6

Tinea nigraTypical brown to black, non-scaling macules on the palmar aspect of the hands. Note: there is no inflammatory reaction Cutaneous mycosesInfections in the living parts of the body:Skin Hair and nailMucocutaneous membranesGenitalia

Tow types can be recognized Dematophytes infectionsNon-dermatophytes infectionsDematophytes 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 dermatophytesDermatophytesMicrosporum Hair, skinEpidermophytonSkin, nailTrichophytonHair, skin, nail

Digest keratin by their keratinasesResistant to cycloheximide

Epidemiology and natural habitatSome have a world-wide distributionSome are restricted to particular regions About 10 species are common causes of human infectionClassified into three groups depending on their usual habitatAnthropophilicHuman is usual hostT. rubrum (foot & nail infections)E. floccosum (foot & nail infections)T. tonsurans (scalp infections)M. audouinii (scalp infections)GeophilicNormal habitat is soilCan cause infections in both humans and animalsMicrosporum gypseumZoophilicOften associated with a particular animal Microsporum canis: cats and dogsTrichophyton verrucosum: horse and cattle DermatophytosisSkin: Circular dry lesionsSlightly raised red scaly marginsSurrounded by red itchy skin Fungus remain restricted to stratum corneumMetabolites provoke inflammationHair: Typical lesions scarring + alopeciaNail: Thickened, deformed, fragile, discolored Sub-ungual debris accumulation 16In most form of dermatophytes, infection in confined to the superficial stratum corneum, nail and hair.However deeper infection involving the dermis can occur, as in kerion, and this can result in the formation of suppurative lesionsDermatophytosis clinical classificationInfection is named according to the anatomic location involvedClinical manifestation (1)RingwormTinea pedis (athlete's foot)Tinea manuum (hands)Tinea corporis (trunk, neck and back)Tinea cruris (hairy skin around the genitilia)Tinea barbae (hairy skin in the face)Tinea capitis (scalp and eyebrows)

Clinical manifestation (2)Favus (scalp)Onychomycosis (nail)

Athlete's foot (Tinea pedis ) Tinea pedis

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Tinea manuum

Tinea manuum

Tinea manuum

Tinea corporis caused by M. canisfollowing contact with infectious cat

Tinea corporis25

Tinea of the groin showing typical erythematous lesions on the inner thighs Tinea of the buttocksTinea cruris

Tinea barbae

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Tinea capitis caused by M. canisfollowing contact with infectious catTinea capitis showing extensive hair losscaused by M. canis Favus and OnychomycosisFavusSpecial form of tinea capitis

OnychomycosisFungal infection of nailThe term "tinea unguium" is used specifically to describe dermatophytic onychomycosis

Favus Tinea capitis showing alopecia

Tinea of the nails caused by T. rubrumLaboratory diagnosis50 % of suspicious materials may be negativeHyphae and/or arthrospores is diagnostic Culture is more reliable:Determined speciesSource of infectionCan be positive even if direct examination is negative 32

Hyphal elements seen in skin scraping preparationManagementDependant on the clinical settingTopical or oral antifungal 34InfectionRecommendedAlternativeTinea unguium[Onychomycosis]Terbinafine 250 mg/day6 weeks for finger nails,12 weeks for toe nails.Itraconazole 200 mg/day/3-5 months or 400 mg/day for one week per month for 3-4 consecutive months. Fluconazole 150-300 mg/ wk until cure [6-12 months].Griseofulvin 500-1000 mg/day until cure [12-18 months].Tinea capitisGriseofulvin 500mg/day[not less than 10 mg/kg/day]until cure [6-8 weeks].Terbinafine 250 mg/day/4 wks.Itraconazole 100 mg/day/4wks. Fluconazole 100 mg/day/4 wksTinea corporisGriseofulvin 500 mg/day untilcure [4-6 weeks], often combined with a topicalimidazole agent.Terbinafine 250 mg/day for 2-4 weeks.Itraconazole 100 mg/day for 15 days or 200 mg/day for 1week.Fluconazole 150-300 mg/week for 4 weeks.Tinea crurisGriseofulvin 500 mg/dayuntil cure [4-6 weeks].Terbinafine 250 mg/day for 2-4 weeks.Itraconazole 100 mg/day for 15 days or 200 mg/day for 1week.Fluconazole 150-300 mg/week for 4 weeks.Tinea pedisGriseofulvin 500mg/dayuntil cure [4-6 weeks].Terbinafine 250 mg/day for 2-4 weeks.Itraconazole 100 mg/day for 15 days or 200 mg/day for 1week.Fluconazole 150-300 mg/week for 4 weeks.Chronic and/orwidespreadnon-responsivetinea.Terbinafine 250 mg/dayfor 4-6 weeks.Itraconazole 200 mg/day for 4-6 weeks.Griseofulvin 500-1000 mg/day until cure [3-6 months].Oral management optionsNon-dermatophytes cutaneous infectionsOnychmycosisIntertrigoMucocutaneous candidiasisThrushVulvo-vaginitis

Intertrigocaused by Candida albicans

Red macerated rash under pendulous breasts is a common presentation of cutaneous candidiasisCandida diaper dermatitis This condition should not be considered a primary Candida infection as it preceded by an irritant dermatitis

39Subcutaneous MycosesSkin, subcutaneous tissues, fascia and boneLocalizedTraumaMore in tropicsMycetoma, chromomycosis and sporotrichosis

MycetomaThis the classical picture of food mycetoma

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Mycetoma42

SporotrichosisA 60-year-old woman developed multiple subcutaneous nodules and abscesses on her right hand and forearm 7 days after finger thorn prick

Sporotrichosis

ClassicalChromoblastomycosis:Fonsecaea pedrosoi

De Hoog, Centraalbureau voor Schimmelcultures

Nodulose chromoblastomycosis(Senegal): Fonsecaea pedrosoi

De Hoog, Centraalbureau voor SchimmelculturesManagement DifficultSurgical excision Itraconazole and other antifungal