1. Mycetoma 2. Sporotrichosis 3. Chromoblastomycosis 4. Phaeohyphomycosis

SUBCUTANEOUS MYCOSES Flashcards by Arriane Camacho

◦Etiologic agents are found as (?) usually native to the soil, on plants, and in decaying vegetation and
wood.

saprobes

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◦Infections can usually be traced to (?)

traumatic inoculation

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◦Typical patient works outdoors, usually (?), in shorts and other lightweight clothing that provides
little protection

without shoes

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◦ Occurring months or years before the lesion appears

SUBCUTANEOUS MYCOSES

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◦Chronic, localized infections of skin and subcutaneous tissue, and adjacent lymphatics

SUBCUTANEOUS MYCOSES

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SUBCUTANEOUS MYCOSES Caused by

traumatic implantation of etiologic agent

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◦Usually remain localized to the subcutaneous tissue or may spread to local nodes through the (?)

lymphatics

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◦Usually of (?) – has to enter the subcutaneous tissue in order to cause disease

low virulence

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◦Most frequently seen in residents of (?)

tropics and subtropics

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◦Fungi are capable of producing (?) which will ulcerate

nodules

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◦Spread the (?) to the lymph channels, producing more nodules

etiologic agent

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◦Such nodules may drain into the skin’s surface, leading to (?)

secondary bacterial infections

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◦For diagnosis, the fungus must be seen in (?) and the fungal morphology must be consistent with the patient’s symptoms

specimens or lesions

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◦Combination of (?) may
be indicated for therapy.

drugs and surgical intervention

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4 kinds of infection

Mycetoma
Sporotrichosis
Chromoblastomycosis
Phaeohyphomycosis

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Tumefaction,
draining sinuses

Mycetoma

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Granules

Mycetoma

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No, localized

Mycetoma

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Ulcers and smooth,
painless nodules

Sporotrichosis

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Asteroid bodies

Sporotrichosis

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Spreads along
lymphatic
channels

Sporotrichosis

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Warty crusted
nodules,
microabscesses

Chromomycosis

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Sclerotic bodies

Chromomycosis

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Possible

Chromomycosis & Phaeohyphomycosis

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Diverse symptoms

Phaeohyphomycosis

No specific element

Phaeohyphomycosis

◦Chronic granulomatous infection

MYCETOMA

◦Lower limbs are most commonly affected

MYCETOMA

→ caused by an actinomycete ◦Nocardia, Actinomadura, Streptomyces, Actinomyces

ACTINOMYCETOMA

→mycetoma caused by a fungus ◦Pseudallescheria boydii, Madurella spp., Exophiala jeanselmei, Acremonium spp., Fusarium spp., Curvularia spp. and occasionally other moulds

EUMYCETOMA (Maduromycosis, Madura foot)

MYCETOMA ETIOLOGIC AGENTS:

◦ Eumycetoma (40%) ◦ Actinomycotic mycetoma (60%)

◦ Madurella mycetomatis (most cases, in arid regions)

Eumycetoma (40%)

◦ Madurella grisea (South America and India)

Eumycetoma (40%)

◦ Pseudallescheria boydii and Scedosporium apiospermum (US)

Eumycetoma (40%)

◦ Nocardia brasiliensis

Actinomycotic mycetoma (60%)

◦ A clinical syndrome characterized by localized, swollen lesions of cutaneous and subcutaneous tissues with later involvement of muscle and bone

MYCETOMA

◦ Triad of symptoms

1. Tumefaction 2. Draining sinus tracts 3. Discharging grains/Granules (300 mm-5mm)

◦ Combination of microcolonies of the causative organism and proteinaceous materials from the host

Grains

Granules (white, yellow or red)

Actinomycotic Mycetoma

◦ Narrow (1 um or less in diameter) intertwined filaments

Actinomycotic Mycetoma

◦ Radially oriented

Actinomycotic Mycetoma

◦ Most numerous at the edge of the granule

Actinomycotic Mycetoma

◦ Nocardia → partially acid fast

Actinomycotic Mycetoma

◦ Actinomadura and Streptomyces → not acid-fast

Actinomycotic Mycetoma

◦ All are gram-positive

Actinomycotic Mycetoma

◦ Stain well with GMS & Giemsa but not with H&E , PAS or Gridley fungus

Actinomycotic Mycetoma

◦Granules (white, yellow brown or black )

EUMYCOTIC MYCETOMA

◦ Contain septate, variously shaped, somewhat distorted hyphae (2 – 6 um in diameter)

EUMYCOTIC MYCETOMA

◦ Accompanied by numerous chlamydoconidia and swollen cells

EUMYCOTIC MYCETOMA

◦ Fungal forms are most commonly visible at the periphery of the granule

EUMYCOTIC MYCETOMA

Histopathologic appearance of “?” due to Madurella mycetomatis using a Gridley stain

black grain mycetoma

H&E STAINED TISSUE SECTION SHOWING BLACKED GRAINED EUMYCOTIC MYCETOMA CAUSED BY

Madurella mycetomatis.

Red

Actinomadura pelletieri

Soft to hard

Actinomadura pelletieri

White

Nocardia brasiliensis, Acremonium falciforme & Pseudallescheria boydii

Soft

Nocardia brasiliensis, Acremonium falciforme, & Pseudallescheria boydii

Yellow

Streptomyces somaliensis

Hard

Streptomyces somaliensis & Madurella spp

Black

Exophiala jeanselmei & Madurella spp.

Brittle

Exophiala jeanselmei

White to Yellow grain species

HYALINE FUNGI

Black grain species

DEMATIACEOUS FUNGI

HYALINE FUNGI

Pseudallescheria boydii Fusarium species Acremonium species

DEMATIACEOUS FUNGI

Exophiala jeanselmei Madurella mycetomatis Madurella grisea Phialophora verrucosa Curvularia species

◦ Anamorph: Scedosporium apiospermum : Graphium species

Pseudallescheria boydii

◦ Colony appear white and fluffy becoming brownish brown to black, reverse is gray to black.

Pseudallescheria boydii

• Produces both sexual and asexual conidia in culture

Pseudallescheria boydii

• Walls are composed of 2-3 layers of septate hyphae

Pseudallescheria boydii

• “Cleistothecia” (Sexual ascocarps)

Pseudallescheria boydii

• 50-200mm, dark-brown to black

Pseudallescheria boydii

• Clavate to subglobose asci(contain up to 8 ascospores)

Pseudallescheria boydii

◦ Single, lemon-shaped annelloconidia

Anamorphs: Scedosporium apiospermum

◦ “Synnemata”

Anamorphs: Scedosporium apiospermum

◦(bundles or tufts of conidiophores

Anamorphs: Scedosporium apiospermum

DIAGNOSIS OF MYCETOMA ◦ Specimens:

◦ Aspiration (best) ◦ Drainage ◦ Tissue biopsy / section

DIAGNOSIS OF MYCETOMA ◦Examination of grains

◦ Size, color, texture, consistency

DIAGNOSIS OF MYCETOMA ◦Direct microscopic examination

◦ 10% KOH ◦ LPCB

DIAGNOSIS OF MYCETOMA ◦Culture

◦ Standard mycological media or aerobic/anaerobic bacterial culture condition

is difficult due to inability of drugs to infiltrate lesions, combination of medicine and surgery is the best

Treatment

◦Eumycotic mycetoma:

Amphotericin B

◦Actinomycotic mycetoma:

Antibiotics

diseases of Sporotrichosis

oBeurmann’s disease oRose gardener’s disease oSchenck’s disease

◦Chronic infection characterized by nodular lesions of the cutaneous & subcutaneous tissues and adjacent lymphatics

Sporotrichosis

Sporotrichosis ◦Etiologic agent:

Sporothrix schenckii

Dimorphic fungus common in soil worldwide

Sporotrichosis

Sporotrichosis oEcologic niche:

Thorny plants, splinters, sphagnum moss, hay

Sporotrichosis oTransmission:

oPenetrating injury or scratch with plant material or soil-contaminated object oRarely through inhalation of conidia oScratch or bite from an infected domestic cat

Sporotrichosis oRisk groups/Factors:

oGardeners oPlant nursery workers oAgricultural workers oChildren (in highly endemic areas) oCat owners and veterinarians

▪ Primary lesions develop at the site of implantation

Fixed cutaneous sporotrichosis

▪ Limbs, hands , Fingers

Fixed cutaneous sporotrichosis

▪ May heal spontaneously with scarring

Fixed cutaneous sporotrichosis

◦ Primary lesions develop at the site of implantation

Lymphocutaneous sporotrichosis

◦ Most common

Lymphocutaneous sporotrichosis

◦ secondary lesions also appear along the lymphangitic channels

Lymphocutaneous sporotrichosis

◦No systemic symptoms are present

Lymphocutaneous sporotrichosis

 typically elevated subcutaneous nodules

Lymphocutaneous sporotrichosis

 regional lymphatics of the forearm

Lymphocutaneous sporotrichosis

◦Osteoarticular

Extracutaneous

◦Pulmonary

Extracutaneous

◦Eyes

Extracutaneous

◦Meningeal forms

Extracutaneous

◦ inhalation of conidia

Pulmonary sporotrichosis

◦ hematogenous dissemination

Pulmonary sporotrichosis

Pulmonary sporotrichosis ◦ Symptoms are non-specific

• sputum production • fever, weight loss and upper-lobe lesion

• Hemoptysis:

massive and fatal.

 Lung lesion:

gradual progression to death

◦ cutaneous lesions

Osteoarticular sporotrichosis

◦ stiffness and pain in a large joint

Osteoarticular sporotrichosis

• Knee, elbow, ankle, wrist

Osteoarticular sporotrichosis

: seldom occurs without arthritis

Osteomyelitis

◦ lesions usually confined to the long bones near affected joints

Osteoarticular sporotrichosis

◦ Multiple dispersed lymphocutaneous lesions and/or visceral dissemination

Disseminated sporotrichosis

Sporotrichosis ◦ Increased risk for:

◦ People living with AIDS (PLWA) ◦ Diabetes ◦ Alcoholism ◦ Sarcoidosis ◦ Long-term corticosteroid therapy and TNF-a antagonists

biopsy material or exudate from granulomatous or ulcerative lesions

Clinical material

Tissue sections

Direct Microscopy

◦ Directly with KOH or calcofluor white stain

Direct Microscopy

◦ GMS→ black cell walls

Direct Microscopy

◦ Periodic acid Schiff stain → red cell walls

Direct Microscopy

◦ Fluorescent Ab stain

Direct Microscopy

Approximately star-shaped w/ rays of eosinophilic materials radiating from a central yeast-like cell

Asteroid bodies

◦ Lymphocutaneous sporotrichosis

Asteroid bodies

◦ Most reliable method of diagnosis

Culture

◦Inhibitory mold agar

Culture

◦ Saboraud’s agar containing antibiotics

◦ Grown at 25 – 30C

Culture

◦ID is confirmed by growth at 35C and conversion to the yeast form

Culture

◦ Low limited value

Serology

◦ Agglutination of yeast cell suspensions or of latex particles coated with antigen

Serology

◦ Sera of infected patients with high titer

Serology

◦ itraconazole

Cutaneous lesions

◦ terbinafine

Cutaneous lesions

◦ Local heat has also been shown to improve cutaneous lesions

Cutaneous lesions

◦ combination of antifungal treatment with Amphotericin B or itraconazole

Extracutaneous forms

◦ with surgical debridement

Extracutaneous forms

: saturated solution of potassium iodide

Second-line therapy

– (mould) young colonies are cream to white with a glabrous texture.

Colony

May develop dark pigment as they age.

Sporothrix schenckii

◦ Mature colonies are flat, leathery to velvety and black with black reverse pigments.

Sporothrix schenckii

Sporothrix schenckii ◦ Yeast form resembles (?)

Candida albicans

◦ Pigments are white, beige or tan.

Sporothrix schenckii

Sporothrix schenckii Identification:

• Hyphomycete • thermal dimorphism • clusters of ovoid, denticulate conidia

Sporothrix schenckii ◦ (?) – delicate, septate hyphae with small, clear pyriform conidia which may surround the tip of the conidiophore to form a rosette

Microscopic

◦ Characterized by verrucoid crusted lesions on the skin

Chromoblastomycosis

◦ If not treated, will elevate to resemble cauliflower (w/ cayenne pepper)

Chromoblastomycosis

Chromoblastomycosis ◦ Causative agents:

◦ Phialophora verrucosa ◦ Fonsecaea pedrosoi ◦ Fonsecaea compacta ◦ Cladophialophora carrionii

◦ development in tissue

Chromoblastomycosis

◦ dematiaceous (brown-pigmented/copper)

Chromoblastomycosis

◦ MOT: traumatic implantation of fungal elements into the skin

Chromoblastomycosis

CHROMOBLASTOMYCOSIS ◦ Similar in their:

◦ Pigmentation ◦ Antigenic structure ◦ Morphology ◦ Physiologic properties

CHROMOBLASTOMYCOSIS ◦ Colonies

◦ Compact, deep brown to black, develop a velvety, often wrinkled surface

CHROMOBLASTOMYCOSIS ◦ In tissue: appear the same → producing spherical brown cells (4 – 12 mm) termed (?) which divide by transverse septation

MURIFORM or SCLEROTIC BODIES

Phialophora verrucosa ◦ (?) : produced from flask-shaped phialides with cup-shaped collarettes

Conidia

◦ Mature, spherical to oval conidia are extruded from the phialide and usually accumulate around it

Phialophora verrucosa

◦ Produce branching chains of conidia by distal (acropetalous) budding

Cladophialophora (Cladosporium) carrionii

◦ Terminal conidium of a chain gives rise to the next conidium by a budding process

Cladophialophora (Cladosporium) carrionii

Cladophialophora (Cladosporium) carrionii ◦ Species are identified based on (?)

DIFFERENCES IN THE LENGTH OF THE CHAINS AND THE SIZE AND SHAPE OF CONIDIA

◦ (?) : elongated conidiophores with long, branching chains of oval conidia

C. carrionii

◦ Produces lateral or terminal conidia from a lengthening conidiogenous cell → a sympodial process

Rhinocladiella aquaspersa

◦ Conidia are elliptical to clavate

Rhinocladiella aquaspersa

◦ Polymorphic genus

Fonsecaea pedrosoi

Fonsecaea pedrosoi ◦ Isolates may exhibit:

(1) phialides, (2) chains of blastoconidia, (3) sympodial, rhinocladiella-type conidiation

◦ Blastoconidia are almost spherical, with a broad base connecting the conidia

Fonsecaea compacta

◦ Smaller and more compact than those of F. pedrosoi

Fonsecaea compacta

◦ (?): becomes verrucous and wart-like with extension along the draining lymphatics

Primary lesion

◦ (?) nodules with crusting abscesses eventually cover the area

◦ Small ulcerations or “(?)” of hemopurulent material are present on the warty surface

black dots

◦ (?) to other parts of the body is rare

Dissemination

◦ (?) can occur due to either local lymphatic spread or to autoinoculation

Satellite lesions

◦ (?) are granulomatous and the dark sclerotic bodies may be seen within leukocytes or giant cells

Lesions

(?): Skin scrapings and/or biopsy

Clinical Material

Direct Microscopy: Skin scrapings:

◦ 10% KOH and Parker ink ◦ calcofluor white mounts

◦ Stains:

◦ H & E ◦ PAS digest ◦ Grocott's methenamine silver (GMS)

◦ Dark brown sclerotic cells which divide by binary fission and not by budding

CHROMOBLASTOMYCOSIS

◦ sclerotic bodies in tissue

CHROMOBLASTOMYCOSIS

◦ (?) is the only reliable means of distinguishing these fungi

Culture ID

◦ primary isolation media: (?)

SDA

◦ clinical history ◦ direct microscopic

◦ Interpretation

◦ Flucytosine (w/ or w/o thiabendazole) ◦ itraconazole ◦ terbinafine

Management

◦(?): margin of uninfected tissue

surgical excision

◦ Colony – olive-green to olive-gray to black with jet black reverse pigment. Surface is spreading and flat with velvety or woolly texture.

Fonsecaea pedrosoi

◦ Microscopic – dark brown, branching hyphae

Fonsecaea pedrosoi

◦Infections characterized by the presence of darkly pigmented septate hyphae in tissue

PHAEOHYPHOMYCOSIS

◦Both cutaneous and systemic infections have been described

PHAEOHYPHOMYCOSIS

◦Clinical forms vary from solitary encapsulated cysts in the subcutaneous tissue to sinusitis to brain abscess

PHAEOHYPHOMYCOSIS

◦Over 100 species of dematiaceous molds

PHAEOHYPHOMYCOSIS

◦Exogenous molds normally existing in nature

PHAEOHYPHOMYCOSIS

PHAEOHYPHOMYCOSIS ◦ More common causes:

◦ Exophiala jeanselmei ◦ Phialophora richardsiae ◦ Bipolaris spicifera ◦ Wangiella dermatitidis

◦ In tissue: hyphae are large (5 – 10 mm) in diameter

PHAEOHYPHOMYCOSIS

◦ Distorted and may be accompanied by yeast cells

PHAEOHYPHOMYCOSIS

◦ Presence of melanin in their cell walls

PHAEOHYPHOMYCOSIS

◦ Specimens are cultured in routine fungal media

PHAEOHYPHOMYCOSIS

PHAEOHYPHOMYCOSIS ◦ (?) is the drug of lchoice

Itraconazole or flucytosine

◦ MOT: traumatic implantation of fungal elements (contaminated soil, thorns or wood splinters

Subcutaneous phaeohyphomycosis

Subcutaneous phaeohyphomycosis ◦ Most common agents:

Exophiala jeanselmei and Wangiella dermatitidis

◦ cystic lesions

Subcutaneous phaeohyphomycosis

◦ overlying verrucose lesions

Subcutaneous phaeohyphomycosis

◦immunosuppressed patient

Subcutaneous phaeohyphomycosis

Paranasal sinus phaeohyphomycosis: ◦ Sinusitis

◦ Bipolaris ◦ Exserohilum ◦ Curvularia

◦ patients with a history of allergic rhinitis

Alternaria

◦ immunosuppression.

Alternaria

Bipolaris ◦ Teleomorph:

Cochliobolus sp

Bipolaris ◦ Colonies

◦ moderately fast growing ◦ Effuse, grey to blackish brown, suede-like to floccose with a black reverse

Bipolaris ◦ Microscopic morphology

◦sympodial development of pale brown pigmented, pseudoseptate conidia

Bipolaris ◦ Conidia

◦straight, fusiform to ellipsoidal, rounded at both ends, smooth to finely roughened and germinating only from the ends (bipolar)

◦ Rapid grower