Mycology

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MYCOLOGYMYCOLOGYELIZABETH P. QUILES, M.D., FPASMAPELIZABETH P. QUILES, M.D., FPASMAP

DEPARTMENT OF MICROBIOLOGYDEPARTMENT OF MICROBIOLOGYOUR LADY OF FATIMA UNIVERSITYOUR LADY OF FATIMA UNIVERSITY

COLLEGE OF MEDICINECOLLEGE OF MEDICINE

SUPERFICIAL MYCOSESSUPERFICIAL MYCOSES

Do not elicit cellular response Do not elicit cellular response colonize colonize only non-living tissuesonly non-living tissues

No pathologyNo pathology generally cause no discomfort to the generally cause no discomfort to the

patientpatient more of cosmetic problemmore of cosmetic problem

Skin infections:Skin infections:

- limited to the outer most layer - limited to the outer most layer of of the stratum corneumthe stratum corneum

Hair infections:Hair infections:

- only the cuticle- only the cuticle

INFECTIONS:INFECTIONS:

A. SKINA. SKIN

1. Pityriasis versicolor1. Pityriasis versicolor

2. Tinea nigra2. Tinea nigra

B. HAIRB. HAIR

1. Black piedra1. Black piedra

2. White piedra2. White piedra

PITYRIASIS VERSICOLORPITYRIASIS VERSICOLOR Chronic, mild, usually asymptomatic Chronic, mild, usually asymptomatic

infection of the stratum corneuminfection of the stratum corneum Etiology : Malassezia furfur Etiology : Malassezia furfur

(Pityrosporum orbiculare)(Pityrosporum orbiculare) Characteristics:Characteristics:

- lipophilic- lipophilic- found in areas rich in sebaceous - found in areas rich in sebaceous glandsglands- part of the normal flora of the skin- part of the normal flora of the skin

Produce azelaic acid Produce azelaic acid inhibit inhibit synthesis of melanin in keratinocytes synthesis of melanin in keratinocytes lesional hypopigmentation lesional hypopigmentation

Increase turn over of stratum Increase turn over of stratum corneum corneum 8 days (Normal= 15 days)8 days (Normal= 15 days)

Predisposing factors:Predisposing factors:

1. corticosteroids1. corticosteroids

2. tropics2. tropics

3. genetic predisposition3. genetic predisposition

4. poor nutritional state4. poor nutritional state

5. excessive sweating5. excessive sweating

6. chronic infections6. chronic infections

Lesions:Lesions:

- involves the upper torso, arms & - involves the upper torso, arms & abdomenabdomen

- hypo- or hyperpigmented macular - hypo- or hyperpigmented macular lesionslesions

- scaly - scaly dry, chalky appearance dry, chalky appearance

- rarely - rarely papular papular

- may involve hair folicles - may involve hair folicles folliculitisfolliculitis

DDx:DDx:1. Pityriasis alba1. Pityriasis alba

- common in children- common in children- usually found in the cheeks- usually found in the cheeks- due to excessive exposure to - due to excessive exposure to

the the sunsun- not due to fungi- not due to fungi- hypopigmented with well-- hypopigmented with well-

defined borders & non-defined borders & non-scalingscaling

- commonly associated with atopy- commonly associated with atopy

2. Vitiligo2. Vitiligo

3. Chloasma3. Chloasma

4. Tinia ciricinata4. Tinia ciricinata

5. Seborrheic dermatitis5. Seborrheic dermatitis

6. Pityriasis rosea6. Pityriasis rosea

7. erythrasma7. erythrasma

Diagnosis:Diagnosis:

- Specimen - Specimen skin scrapings skin scrapings

1. microscopic 1. microscopic “spaghetti & “spaghetti & meatballs” appearancemeatballs” appearance

2. Wood’s lamp 2. Wood’s lamp golden yellow golden yellow fluorescencefluorescence

3. Culture3. Culture

TREATMENT :TREATMENT :

1. keratolytic agents 1. keratolytic agents Whitfield’s Whitfield’s ointment or salicylic acidointment or salicylic acid

2. 25% sodium thiosulfate + 1% 2. 25% sodium thiosulfate + 1% salicylic acidsalicylic acid

3. miconazole3. miconazole

4. selenite disulfide 4. selenite disulfide

TINEA NIGRATINEA NIGRA Etiology: Exophiala wernickiiEtiology: Exophiala wernickii Characteristics:Characteristics:

- dimorphic- dimorphic

- produce melanin - produce melanin brown to black color brown to black color

- initially grows as yeast with many cells - initially grows as yeast with many cells in in various stages of cell division various stages of cell division two- two-celled oval structurescelled oval structures

- older colonies - older colonies hyphae hyphae mycelia & mycelia & conidiaconidia

Lesions:Lesions:

- asymptomatic- asymptomatic

- well-demarcated brown to black - well-demarcated brown to black non-scaly macular lesions non-scaly macular lesions peripheral extensionperipheral extension

- deeper pigmentation at the - deeper pigmentation at the advancing bordersadvancing borders

- often seen in the palms & soles- often seen in the palms & soles

Diagnosis:Diagnosis:

- microscopic- microscopic

darkly pigmented yeastlike cells darkly pigmented yeastlike cells & hyphal fragments& hyphal fragments

two-celled yeasts two-celled yeasts (annelioconidia)(annelioconidia)

DDx:DDx:

1. malignant melanoma1. malignant melanoma

2. junctional nevus2. junctional nevus

3. pigmentation of Addison’s disease3. pigmentation of Addison’s disease

4. contact dermatitis4. contact dermatitis

5. chemical staining5. chemical staining

BLACK PIEDRABLACK PIEDRA Etilogy: Piedraia hortaeEtilogy: Piedraia hortae Lesion: Lesion:

- hard nodules along the infected - hard nodules along the infected hair shafthair shaft

- nodules have hard carbonaceous - nodules have hard carbonaceous consistency & house asciconsistency & house asci

DDx: nits of pediculosis & abnormal DDx: nits of pediculosis & abnormal hair growthhair growth

WHITE PIEDRAWHITE PIEDRA Etiology: Trichosporon beigeliiEtiology: Trichosporon beigelii Affects the hairs of the scalp, Affects the hairs of the scalp,

mustache & beardmustache & beard Characterized by cream-colored soft Characterized by cream-colored soft

pasty growths along the infected pasty growths along the infected hair shaftshair shafts

Growths occur as sleeve or collarette Growths occur as sleeve or collarette around the hair shaftaround the hair shaft

DDx: trichomycosis axillaris & nitsDDx: trichomycosis axillaris & nits

TREATMENTTREATMENT Skin infections:Skin infections:

- keratolytic agents- keratolytic agents

- selenium disulfide (hyposulfite or - selenium disulfide (hyposulfite or thiosulfate)thiosulfate)

- salicylic acid- salicylic acid

- antifungal agents - antifungal agents miconazole miconazole Hair infections:Hair infections:

- shaving or cropping the infected hairs- shaving or cropping the infected hairs

- proper hygiene- proper hygiene

DISEASEDISEASE ORGANISMORGANISM TISSUETISSUE CLINICAL FEATURESCLINICAL FEATURES

Pityriasis Pityriasis versicolorversicolor

Malassezia Malassezia furfurfurfur

SkinSkin Hyper- or Hyper- or hypopigmented macular hypopigmented macular lesions, scalylesions, scaly

Chalky, branny Chalky, branny appearanceappearance

Upper torso of the bodyUpper torso of the body

Tinea NigraTinea Nigra Exophiala Exophiala wernickiiwernickii

SkinSkin Well-demarcated gray to Well-demarcated gray to black macular lesionsblack macular lesions

Palms & solesPalms & soles

Black Black piedrapiedra

Piedraia Piedraia hortaehortae

HairHair Hard, gritty, brown to Hard, gritty, brown to black concretions along black concretions along the hair shaftthe hair shaft

White White piedrapiedra

Trichosporon Trichosporon beigeliibeigelii

HairHair Soft, white to creamy Soft, white to creamy yellow granules yellow granules sleeve-like collarette sleeve-like collarette along the hair shaftalong the hair shaft

CUTANEOUS MYCOSESCUTANEOUS MYCOSES(DERMATOPHYTOSIS)(DERMATOPHYTOSIS)

Involve the skin, hair & nailsInvolve the skin, hair & nails Restricted to keratinized layers of Restricted to keratinized layers of

integument & its appendages integument & its appendages Keratinophilic fungiKeratinophilic fungi

Have the ability to use keratin as Have the ability to use keratin as substratesubstrate

Clinical manifestations Clinical manifestations Tinea or Tinea or ringworm ringworm due to serpentine or due to serpentine or annular lesions they produceannular lesions they produce

3 Genera:3 Genera:

1. Microsporum1. Microsporum

- produce both micro- & - produce both micro- & macroconidia macroconidia

- predominantly macroconidia - predominantly macroconidia (rough-walled)(rough-walled)

- infects the skin & hair- infects the skin & hair

2. Trichophyton2. Trichophyton

- produce both micro- & - produce both micro- & macroconidiamacroconidia

- predominantly microconidia - predominantly microconidia (smooth-walled)(smooth-walled)

- infects the skin, hair & nails- infects the skin, hair & nails

3. Epidermophyton3. Epidermophyton

- produce only macroconidia - produce only macroconidia (smooth-walled)(smooth-walled)

- infects the skin & nails- infects the skin & nails

CLASSIFICATION (accg to source):CLASSIFICATION (accg to source):

1. GEOPHILIC – soil1. GEOPHILIC – soil

2. ZOOPHILIC – domestic & wild 2. ZOOPHILIC – domestic & wild animals animals & birds& birds

3. ARTHROPOPHILIC – humans & 3. ARTHROPOPHILIC – humans & their habitatstheir habitats

Importance Importance diagnostic & diagnostic & prognosticprognostic

Anthropophilic dermatophytes Anthropophilic dermatophytes cause chronic infections & difficult cause chronic infections & difficult to treatto treat

Geophilic & zoophilic dermatophytes Geophilic & zoophilic dermatophytes cause inflammatory lesions cause inflammatory lesions

but but respond well to therapy & respond well to therapy & occasionally heal spontaneouslyoccasionally heal spontaneously

CLASSIFICATION ACCORDING TO CLASSIFICATION ACCORDING TO ECOLOGICAL NICHEECOLOGICAL NICHE

ANTHROPOPHILIC ANTHROPOPHILIC DERMATOPHYTESDERMATOPHYTES

ZOOPHILIC ZOOPHILIC DERMATOPHYTESDERMATOPHYTES

GEOPHILIC GEOPHILIC DERMATOPHYTESDERMATOPHYTES

M. audouiniiM. audouinii

M. mentagrophytesM. mentagrophytes

T. rubrumT. rubrum

T. tonsuransT. tonsurans

T. violaceumT. violaceum

E. floccosumE. floccosum

M. canisM. canis

M. equinumM. equinum

M. gallinaeM. gallinae

T. equinumT. equinum

T. mentagrophytesT. mentagrophytes

M. cookeiM. cookei

T. gypseumT. gypseum

M. fulvumM. fulvum

M. nanumM. nanum

INFECTIONSINFECTIONS

Tinea pedis – feetTinea pedis – feet Tinea capitis – scalpTinea capitis – scalp Tinea manus – handsTinea manus – hands Tinea unguium – nailsTinea unguium – nails Tinea corporis – bodyTinea corporis – body

Other infections are given special Other infections are given special names: names:

- Favus (T. schoenleinii) - Favus (T. schoenleinii)

- Tokelau (T. concentricum)- Tokelau (T. concentricum)

Fungal elements in infected hairs Fungal elements in infected hairs may appear as may appear as endothrix infection endothrix infection or ectothrix infectionor ectothrix infection

TINEA CORPORISTINEA CORPORIS

Also known as tinea circinataAlso known as tinea circinata Ringworm of the body outside the Ringworm of the body outside the

body folds, palms & solesbody folds, palms & soles Lesions are circular, erythematous Lesions are circular, erythematous

with elevated papular borders & with elevated papular borders & scalyscaly

With central clearingWith central clearing Usually appear first on sweaty areasUsually appear first on sweaty areas

DDx: DDx:

1. nummular eczema1. nummular eczema moist moist with with vesicles & crustingvesicles & crusting

2. plaque psoriasis 2. plaque psoriasis thicker, thicker, silvery white scales silvery white scales

3. Hansen’s disease 3. Hansen’s disease patchy patchy anesthesia & non-scalyanesthesia & non-scaly

4. granuloma annulare 4. granuloma annulare no- no-scaly scaly & not erythematous& not erythematous

TINEA CRURIS (JOCK ITCH)TINEA CRURIS (JOCK ITCH)

Affects the body folds Affects the body folds integluteal integluteal fold, axillae & genitocrural foldfold, axillae & genitocrural fold

More common in males than femalesMore common in males than females Annular plaques in the genitocrural Annular plaques in the genitocrural

fold fold upper inner thighs, lower upper inner thighs, lower abdomen or buttocksabdomen or buttocks

The genitals are sparedThe genitals are spared DDx: allergic contact dermatitis, DDx: allergic contact dermatitis,

seborrheic dermatitis, psoriasisseborrheic dermatitis, psoriasis

TINEA PEDIS TINEA PEDIS (ATHLETE’S FOOT)(ATHLETE’S FOOT)

Most common type Most common type Usually involves the 3Usually involves the 3rdrd & 4 & 4thth toe web toe web 44thth & 5 & 5thth toes may also be affected toes may also be affected Varied clinical presentation Varied clinical presentation

maceration of the interdigital maceration of the interdigital spacespace Associated with hyperhidrosisAssociated with hyperhidrosis

Types:Types:1. Hyperkeratotic type 1. Hyperkeratotic type present present with chronic scaling, with with chronic scaling, with fissuring fissuring over the sole, heal & over the sole, heal & sides of the sides of the footfoot moccasin moccasin configurationconfiguration2. Vesiculobullous type 2. Vesiculobullous type vesicles on toes & solesvesicles on toes & soles

DDx: dyshidrotic eczema, contact DDx: dyshidrotic eczema, contact dermatitis, psoriasisdermatitis, psoriasis

TINEA CAPITISTINEA CAPITIS

Common in childrenCommon in children Fungi invade the hair cortex Fungi invade the hair cortex

endothrix infection endothrix infection hair breakage hair breakage broken hair stubs on a scaly patch broken hair stubs on a scaly patch “black dot” capitis or alopecia “black dot” capitis or alopecia

Ectothrix infection Ectothrix infection not much hair not much hair breakage breakage highly inflammatory highly inflammatory nodular, boggy erythematous nodular, boggy erythematous swelling swelling kerion kerion

DDx:DDx:

1. alopecia areata 1. alopecia areata bald spot bald spot smooth & non-scalysmooth & non-scaly

2. seborrheic dermatitis2. seborrheic dermatitis

3. psoriasis 3. psoriasis alopecia is not alopecia is not common & scales are thickercommon & scales are thicker

4. Trichotillomania 4. Trichotillomania neurotic neurotic compulsive hair pulling; broken stubs compulsive hair pulling; broken stubs of hair at varying lengthsof hair at varying lengths

TINEA BARBAETINEA BARBAE

Dermatophytosis of the beard areaDermatophytosis of the beard area Lesions are red, dry & scalyLesions are red, dry & scaly Usually highly inflammatoryUsually highly inflammatory Similar to folliculosisSimilar to folliculosis DDx: sycosis barbae – due to DDx: sycosis barbae – due to

StaphylococcusStaphylococcus

TINEA UNGUIUMTINEA UNGUIUM

Also known as onychomycosisAlso known as onychomycosis Causes accumulation of Causes accumulation of

hyperkeratotic material under the hyperkeratotic material under the nail, deformities & white nail, deformities & white discoloration of the nail plate with discoloration of the nail plate with separation or lifting from the nail bedseparation or lifting from the nail bed

Toenails are commonly affectedToenails are commonly affected

TINEA FACIEITINEA FACIEI

Dermatophytosis of nonbearded Dermatophytosis of nonbearded areas of the faceareas of the face

Lesions Lesions annular patch or plaque annular patch or plaque Papules & pustules may be present Papules & pustules may be present

(acquired from household pets)(acquired from household pets) DDx: allergic contact dermatitis, DDx: allergic contact dermatitis,

seborrheic dermatitis & discoid lupus seborrheic dermatitis & discoid lupus erythematosuserythematosus

TINEA MANUUMTINEA MANUUM

Affects the interdigits, dorsa & palm Affects the interdigits, dorsa & palm of one or both handsof one or both hands

Dry, hyperkeratotic scaling, fissuring Dry, hyperkeratotic scaling, fissuring with or without vesicles on the palmswith or without vesicles on the palms

Annular lesions in the dorsaAnnular lesions in the dorsa Occasionally Occasionally hyperkeratosis of one hyperkeratosis of one

palm may be associated with the palm may be associated with the same lesion on both soles same lesion on both soles “two “two feet-one hand” syndromefeet-one hand” syndrome

TINEA IMBRICATATINEA IMBRICATA(TOKELAU)(TOKELAU)

Etiology: T. concentricumEtiology: T. concentricum Common in the Pacific IslandsCommon in the Pacific Islands Lesions: Lesions:

- concentric rings of red & scaly - concentric rings of red & scaly plaques plaques

Commonly located on the Commonly located on the widespread widespread of the trunkof the trunk

EPIDEMIOLOGYEPIDEMIOLOGY

Tinea capitis is more common in childrenTinea capitis is more common in children Tinea pedis is more common in adultsTinea pedis is more common in adults Tinea capitis, pedis & cruris are more Tinea capitis, pedis & cruris are more

common in malescommon in males Tinea unguium of the hand is more Tinea unguium of the hand is more

common in womencommon in women Tinea unguium of the feet is more Tinea unguium of the feet is more

common in malescommon in males

Microscopic Characteristics of Common Microscopic Characteristics of Common FungiFungi

M. FurfurM. Furfur Spaghetti & meatballsSpaghetti & meatballs

E. WernickiiE. Wernickii Two-celled yeast (annelioconidia)Two-celled yeast (annelioconidia)

M. CanisM. Canis Spindle-shaped, thick, rough-walled Spindle-shaped, thick, rough-walled macroconidia (5-15 cells), w/ terminal macroconidia (5-15 cells), w/ terminal knob & spiny tipsknob & spiny tips

M. GypseumM. Gypseum Blunt terminal ends, thin, rough-walled Blunt terminal ends, thin, rough-walled conidiaconidia

T. MentagrophytesT. Mentagrophytes En grappe microconidia w/ coiled En grappe microconidia w/ coiled hyphaehyphae

T. RubrumT. Rubrum Teardrop or enthyrse microconidia; no Teardrop or enthyrse microconidia; no macroconidiamacroconidia

T. ScheoenleiniiT. Scheoenleinii Antler nail-head hyphae or favic Antler nail-head hyphae or favic chandelier; no micro- or macroconidiachandelier; no micro- or macroconidia

E. floccosumE. floccosum Smooth, thin-walled macroconidia in Smooth, thin-walled macroconidia in clustersclusters

Macroconidia of Microsporum canisMacroconidia of Microsporum canis

Macroconidia of M. gypseumMacroconidia of M. gypseum

Macroconidia of Epidermophyton Macroconidia of Epidermophyton floccosumfloccosum

Micro and Macroconidia of Trichophyton Micro and Macroconidia of Trichophyton mentagrophytesmentagrophytes

““rosette pattern” of conidia in Sporothrix rosette pattern” of conidia in Sporothrix schenckiischenckii

TINEA CORPORISTINEA CORPORIS

TINEA CORPORISTINEA CORPORIS

TINEA UNGUIUMTINEA UNGUIUM

TINEA PEDISTINEA PEDIS

TINEA PEDISTINEA PEDIS

TINEA FACIEITINEA FACIEI

TINEA CRURISTINEA CRURIS