Superficial Cutaneous

Click here to load reader

  • date post

  • Category


  • view

  • download


Embed Size (px)

Transcript of Superficial Cutaneous



fungal infections acquired by man through inhalation or inoculation by trauma into the skin


only about 100 species of yeasts and molds cause disease in humans and animals

Dermatophytes and Candida species are commonly transmitted between humans

RISK FACTORSImmunocompromised due to long-term antibiotic treatment Use of immunosuppressive drugs: Cancer chemotherapy drugs, Corticosteroids Drugs that prevent organ rejection Disorders: AIDS, Burns, if extensive ; Diabetes ; Hodgkin lymphoma or other lymphomas; Kidney failure ; Lung disorders, such as emphysema ; Leukemia


Superficial Mycoses Cutaneous Mycoses Subcutaneous Mycoses Systemic Mycoses Opportunistic Mycoses



skin, hair, or nails

No cellular response from host No pathological changes Host unaware

Disease Pityriasis versicolor Seborrhoeic dermatitis including Dandruff Follicular pityriasis Tinea nigra White Piedra Black Piedra

Causative Organisms Malassezia furfur (a lipophilic yeast)

Incidence Common

Exophiala werneckii Trichosporon beigelii Piedraia hortae

Rare Common Rare

Pityriasis versicolora chronic mild superficial infection of the stratum corneum

Causative Agent: Malassezia furfur complex ( M globosa, M restricta)lipophilic yeast, young adults isolated from normal skin and scalp Distribution: Worldwide, more common in TROPICAL


Pityriasis versicolor Lesions:discrete, serpentine hyper or hypopigmented maculae on skin Chest, upper back, arms, abdomen Scaly, chalky , inflammation, and irritation are minimal enlarge or coalesce

Pityriasis versicolor Diagnosis:Direct microscopic examination (10-20% KOH,stained with calcofluor white)

Pityriasis versicolor Diagnosis: Woods lamp

Culture is unnecessary SDA overlaid with peanut oil, olive oil Dixons agar (glycerol-mono-oleate)

Pityriasis versicolor Treatment:

Selenium sulfide (1%) applied daily Oral or topical azolesMild fungicides Miconazoles

Opportunistic fungemiacatheter acquired infection common in neonates & adults undergoing lipid replacement therapy small embolic lesions in the lungs and other organs Diagnosis: Blood drawn back from catheter, culture tip of catheter Treatment: replace fluid and intravenous catheter

Pityriasis folliculitisfollicular papules and pustules Back, chest, upper arms, neck, more seldom the face Itchy after sun exposure

Pityriasis folliculitis Diagnosis and TreatmentScrapings or biopsy : yeasts at the mouths of infectedfollicles

Topical imidazoleIf lesions are extensive, ketoconazole, itraconazole Prophylactic treatment 1x or 2x week to prevent relapse

Seborrheic DermatitisHost factors Parkinson s disease, AIDS erythema and greasy scaling Scalp, face, eyebrows, ears, upper trunk topical imidazole, ketoconazole, relapse is common

Malassezia DermatitisCausative Agent: Malassezia pachydermatis

Phytosporum canisCommon Microclimate alterations yeast in canine skin host defenses are down and external ear canal

little zoonotic potential

Ketoconazole, miconazole

Malassezia Dermatitis Lesions:Pruritus Greasiness Lichenification Strong body odor Otitis externa Staphylococcal pyoderma

Peanut-shaped yeast

M pachydermatis from a dog ear

TINEA is Latin for growing worm.

Tinea Nigra(Tinea Nigra Palmaris) Causative Agent: Hortaea (Exophiala) werneckii Chronic, saprophyte in asymptomatic soil, compost, young women, warm coastal regions, tropical humus and wood Distribution: Central and South America, Australia, Southeast Asia, Africa

Tinea Nigra Lesions:

dark (brown to black) on palm, well demarcated macular lesions No inflammatory reaction

Tinea Nigra Diagnosis:Direct microscopic examination (KOH) brown to olivaceous Melanized cell wall septate hyphae 2-celled yeast

mucoid yeast-like shiny black

Culture on SDA

Tinea Nigra Treatment :Whitfield s ointment (benzoic acid compound) 2% salicylic acid, 3% sulfur azole antifungal drugs tincture of iodine Miconazole nitrate, imidazoles, triazoles

PIEDRAfrom the Spanish word stone fungus infection of the hair shaft firm, irregular nodules multiple infections of the same strand

BLACK PIEDRACausative Agent : Piedraia hortae soil is source of infection humans and primates Distribution: Africa, Asia, Central, South America can be confused with trichorrhexis nodosa and trichonodosis Ascomycetous fungi

BLACK PIEDRA Lesions:Scalp hair beard and moustache axilla and groin hairs

discrete, hard, gritty , brown to black nodules

BLACK PIEDRA Diagnosis & Treatment:Direct microscopic examination (KOH)

Round to oval asci, curved to fusiform ascospores Dark septate hyphae

Culture on SDA-CC Very slow, dark brown to black Heaped center with flat periphery Short aerial mycelium

BLACK PIEDRA Diagnosis & Treatment:Usually shaving or cutting hair short


WHITE PIEDRACausative Agent : Trichosporon beigelli, T cutaneum Distribution : South America,Asia N. America & Europe (sporadic)

soil, stagnant water, decaying fruit, spoiled food, sputum and body surfaces, horses Face, axilla, genitals : common Scalp, eyebrows, eyelashes : less common


yellowish to white, soft, beige or greenish,irregular transparent sheath

WHITE PIEDRA DiagnosisDirect microscopic examination (10% KOH or 25% NAOH plus 5% glycerin) Hyaline septate hyphae Oval/rectangular arthroconidia Blastoconidia

Culture on SDA with chloramphenicol, without cycloheximide

rapid Cream-colored Soft, membranous Wrinkled radial furrows Irregular folding

WHITE PIEDRA Treatment:Usually shaving or cutting hair short 1:200 bichloride mercury, benzoic acid & salicylic acid, 3% sulfur ointment, 2% Formalin, combinations


keratinized tissue restricted to non viable skin unable to grow at 37 C unable to grow in presence of serum Host specific : keratinases, elastases, enzymes


Dermatophytoses: infection of skin, hair and nailsnonviable skin: only hyphae and arthroconidia sexual state belong to a single genus Arthroderma


Presence of macroconidia; its characteristics; large, spindle shaped,multicellul ar form on ends of hyphae pencil shaped macroconidia with blunt ends are rare


Presence of microconidia, its characteristics

Special name

Site of infection


rough walled

sheath of skin, hair, spores rare in nails


smooth walled

ghost hair


only one- to five-celled,club shaped macro are formed in smooth greenish-yellow walled colony which mutates readily to form a sterile white growth


ghost of skin

skin and nails, never hair


GEOPHILIC : soil ; decompose keratinaceous debris ZOOPHILIC: parasitic on animals

ANTHROPHILIC: man is exclusive host

CLINICAL MANIFESTATIONSTinea or ringworm raised circular lesions Tinea pedis : foot Tinea capitis: head Tinea corporis: body Tinea unguium: nails Tinea cruris: crotch

Tinea pedis(Athletes foot) Etiologic Agents: Trichophyton mentagrophytes, Trichophyton rubrum, Epidermophyton floccosum, Trichophyton interdigitale chronic infection of the toe webs matting or carpets with desquamated infectious scales

Moccasin type by E floccosum (left) ; vesicular type by Tinea pedis by T rubrum (left) ; severe maceration T interdigitale (right) (right)

Tinea unguium (Onychomycosis)Etiologic Agents: T rubrum, T interdigitale invasion of the nail plate one or more nails of the hands or feet Onychomycosis : nondermatophytic fungal nail infection (yeasts)

T rubrum

Tinea corporisEtiologic Agents: E floccosum, T rubrum, T tonsurans, M canis and M gypseum (geophilic infections) glabrous or non hairy areas of the skin grow within dead keratinized tissue

M canis ; after exposure to infectious kittens

Tinea crurisEtiologic Agents: E floccosum, T rubrum, T interdigitale proximal medial thighs, perineum and buttocks

Jock Itch - more common in males military personnel, sharing of towels and clothing

Erythematous lesions on the thighs

Granular strain

Downy strain

Tinea capitisscalp and hair begin at scalp with hyphal invasion 2 types: Ectothrix and Endothrix

Ectothrix InfectionEtiologic agents: M. canis, M. gypseum, T. equinumand T. verrucosum

around hair shaft chain of spores imparting greenish to silvery fluorescence

Endothrix InfectionEtiologic agents: T tonsurans, T. violaceum within hair shaft black dot, weakened and break All are anthrophilic


Kerion: severe combined inflammatory andhypersensitivity reaction


Favus: acute inflammatory infection of hair follicle leading to scrutula or crustsT. schoenleinii

Tinea barbaeEtiologic agents: T mentagrophytes

bearded region

zoophilic dermatophyte : pyogenic infection

Tinea manuumInterdigital areas and palmar surfaces Occurs almost exclusively in adults Itchiness is moderate and minimal Slow progress : months to years

1st pattern : ringworm pattern at dorsum of hand

2nd pattern : chronic scaling at palmar surfaceDry, hyperkeratotic, thickened, fine, silvery white scales

Tinea imbricataTokelau

Etiologic agents: Trichophyton concentricum Distribution: Southwest Polynesia, Melanesia,Sou