Superficial, Cutaneous and Subcutaneous Fungal Infections

Jarrod Fortwendel, PhDDepartment of Microbiology and Immunology

jfortwendel@southalabama.eduMSB 2142

Nov. 18-22, 2013

Tinea Capitis in an Adult Woman

• 87 yo woman presents to her doctor with a 2-year history of puritic, painful, scaling scalp eruption and hair loss

• Previous treatment included numerous courses of systemic antibiotics and prednisone without success

• Social history: recently acquired several stray cats that she kept inside her home

• Physical exam: numerous pustules throughout the scalp, diffuse erythema, crusting, and scale extending to neck. Extremely sparse scalp hair and prominent posterior lymphadenopathy. No nail pitting.

• Wood light positive• Presumptive diagnosis: Tinea Capitis

Cutaneous (and Superficial) Mycoses

• Infections of the skin, hair, nail

• Invades keratinized layers• Tinea – latin for “worm”• Subgroups of infections

1. Dermatophytoses – “classical ringworm”2. Non-dermatophytic cutaneous mycoses…

“the other superficial group”

The Dermatophytes – Classical ringworm - #1 mould infection

• Epidemiology– Anthropophilic, zoophilic, geophilic– Transmissible– Invade skin, hair and nails– Collectively called “tinea”– 3 major Genera:• Trichophyton• Epidermophyton• Microsporum

The Dermatophytes – Classical ringworm - #1 mould infection

• Epidemiology– Anthropophilic, zoophilic, geophilic– Transmissible– Invade skin, hair and nails– Collectively called “tinea”– 3 major Genera:• Trichophyton• Epidermophyton• Microsporum

T. rubrumT. mentagrophytes

Cause 80-90% of cases worldwide

The Dermatophytes: Pathogenesis

• Virulence factors and pathogenesis:

– Infectious element• Arthroconidia

– Keratin utilization• Keratinophilic and keratinolytic

– Hair invasion/colonization• Endothrix, Ectothrix, Favic

Clinical: Classified by anatomical site affected

• Tinea capitis– Microsporum spp. –

• M. audouinii, gray patch ringworm• M. canis, M. gypseum

• Tinea corporis – point lesion centrifugal spread – anywhere on body from eyebrow and neck “southward”– Trichophyton spp., Epidermophyton, (Also Candida)

• Tinea pedis – cosmopolitan– Trichophyton spp., Epidermophyton

• Tinea unguium– Often as a secondary infected site– Almost any dermatophyte, esp Trichophyton rubrum, (Also Candida)

Tinea capitis

Tinea corporis

Tinea imbricataEtiology: Trichophyton concentricum

Tinea cruris

Tinea cruris

Tinea unguium - onychomycosis

Tinea barbae

Tinea manum

Dermatology Image Atlas: Dermatology Images - dermatlas.med.jhmi.edu

Tinea pedis

The Dermatophytes - Zoophilic

The Dermatophytes - Zoophilic

Laboratory Diagnosis

• Requires demonstrating hyphae/arthroconidia from skin, hair, nails

• Direct preparation:• Lesion scrapings/hair examined by calcofluor/KOH

• Alternatively - Wood’s Light: • UV irradiation of infected hair, false positive/negative

• Report: Hyphal fragments/arthrocondida seen

• Culture: SDA +; SDA-CC + LPCB

Direct KOH prep: Hyphal fragments seen

http://www.mycology.adelaide.edu.au/virtual/2009/ID2-Oct09.html

The Dermatophytes: Morphology

Epidermophyton spp. - Smooth walled macroconidia borne in clusters of 2 or 3; no microconidia

Trichophyton spp. - Rare, smooth, thin-walled macroconidia; numerous spherical or teardrop shaped microconidia

Microsporum spp. - Numerous, large, thick, rough-walled macroconidia; rare microconidia

Treatment of the dermatophytoses• Localized cutaneous - topical agents

– Clotrimazole (Lotrimim), Miconazole (micatin)– Tolnaftate (tinactin), terbinafine (lamisil)

• Hair, nails – oral therapy– Fluconazole, itraconazole, griseofulvin

• Griseofulvin – Concentrates in newly keratinized layers of cells– Virtually eradicated epidemic tinea capitis; used in tinea unguium

and extensive infections.

• Recurrences are common

Non-dermatophytic Onychomycosis:

• Candida spp.– Fluconazole

• Scopulariopsis spp.• Scytalidium spp.

– partial surgical nail removal + antifungal

• **Possible other nail pathogens:– Aspergillus spp.– Fusarium spp.– Acremonium spp. **nail pathogen vs. saprobe on abnormal nail material ** Must have: > 1 KOH positive!! > culture positive isolation of same agent!!

**R/O fungal contamination of the culture**

Case resolution…

• Wood Light – positive• Skin biopsy– Enterococcus spp. and Trichophyton tonsurans– Endothrix dermatophyte infection

• Treated with griseofulvin and Selsun• New hair growth and resolution of pustular

eruption at 2 week follow-up• Treatment continued for 8 weeks with complete

hair re-growth and no permanent alopecia

Superficial Mycoses

• Tinea versicolor – AKA pityriasis versicolor– Malessezia furfur

• Tinea nigra palmaris– Hortaea (Exophiala) werneckii

• Piedra – black– Piedraia hortai

• Piedra – white– Trichosporon beigelii

Superficial Mycoses

• Tinea versicolor – AKA pityriasis versicolor– Malessezia furfur• Very common – up to 60% infected population in

certain tropical environments• Most common in tropic and subtropics• Person-to-person transfer• Liopophilic fungus that degrades lipids to produce acids

that damage melanocytes = hypopigmented patches w/ dark skin, pink or brown w/ light skin• Little-to-no host immune reaction

Tinea (pityriasis) versicolorChest

Back

Skin Scraping – Direct Prep (KOH)

• Diagnosis made by direct exam• Does not culture routinely - lipophilic• Treatment: 2.5 % Selenium sulfide or topical cream

azoles – Severe cases: Oral ketoconazole

“collarette”

“Spaghetti and meatballs”

Superficial Mycoses• Tinea versicolor – AKA pityriasis versicolor– Malessezia furfur

• Tinea nigra–Hortaea (Exophiala) werneckii

• Piedra – black– Piedraia hortai

• Piedra – white– Trichosporon beigelii

Superficial Mycoses• Tinea versicolor – AKA pityriasis versicolor– Malessezia furfur

• Tinea nigra–Hortaea (Exophiala) werneckii– Superficial phaeohyphomycosis– Solitary, irregular, pigmented macule usually on palms

or soles– Tropic or subtropic– Traumatic inoculation– Not contagious– Can resemble a malignant melanoma

Tinea nigra – H. werneckii

http://www.mycology.adelaide.edu.au/virtual/2007/ID2-Feb07.html http://www.mycology.adelaide.edu.au/virtual/2007/ID2-Feb07.html

1. KOH prep = pigmented hyphae and yeast

2. Culture = dematiaceous, yeast-like colony in 3 weeks

3. Microscopic = two-celled, cylindrical, yeast-like cells

4. Treatment: Topical azoles

Superficial Mycoses• Tinea versicolor – AKA pityriasis versicolor– Malessezia furfur

• Tinea nigra palmaris– Hortaea (Exophiala) werneckii

• Piedra – black–Piedraia hortae

• Piedra – white– Trichosporon beigelii

Superficial Mycoses• Tinea versicolor – AKA pityriasis versicolor

– Malessezia furfur• Tinea nigra palmaris

– Hortaea (Exophiala) werneckii

• Piedra – black–Piedraia hortae• Tropical, poor hygiene, uncommon• Small, dark nodules surrounding hair shaft• Clumped together by cement-like substance with asci and

ascospores• Diagnosis = direct exam• Treatment = haircut, washing

Superficial Mycoses• Tinea versicolor – AKA pityriasis versicolor

– Malessezia furfur• Tinea nigra palmaris

– Hortaea (Exophiala) werneckii• Piedra – black

– Piedraia hortai

• Piedra – white– Trichosporon beigelii

– Tropical and subtropical, poor hygiene– Affects hairs of groin and axillae– Forms soft, white/brown swelling on hair shaft– Shaving and washing

Superficial Mycoses• Tinea versicolor – AKA pityriasis versicolor– Malessezia furfur

• Tinea nigra palmaris– Hortaea (Exophiala) werneckii

• Piedra – black– Piedraia hortai

• Piedra – white– Trichosporon beigelii

• Other non-dermatophytic (several)– E.g. Candida, Fusarium, and more…

Subcutaneous mycoses

• AKA: Inoculation Mycoses – normal soil inhabitants

• Primary infection in deep skin, muscle or connective tissue

• Slowly progressive and chronic, usually confined

• Not transmissible

• Subgroups of subcutaneous mycoses I. Sporotrichosis II. Chromoblastomycosis/PhaeohyphomycosisIII. MycetomaIV. Subcutaneous Zygomycosis

Sporotrichosis – Sporothrix schenkii

• Epidemiology : – Decaying vegetation, esp used for mulching– Enters via splinters, thorn pricks

-Occupational hazard• Clinical Aspects:

– Primary nodular lesion necrotic ulcer, suppurative– Proximal lymphatics may chronically infect (dissemination rare)

• Sporothrix schenckii: – Direct prep: RARE blastoconidia– Sporothrix is a thermal dimorph– At RT: DEMATIACEOUS colony, HYALINE septate hyphae, delicate lateral

conidiophores w/ delicate rosettes of conidia– At 37°C in vivo & in vitro: oval, cigar-shaped blastoconidia.

• Treatment:– Itraconazole

Chromoblastomycosis• Epidemiology:

– tropics – PR, Cuba, Costa Rica and Brazil– Soil saprobes; dematiaceous fungi– Trauma is required, occurs when shoes are rarely worn

• Clinical Manifestations: – Not contagious– Incubation unknown– Chronic skin and subcutaneous infections– Small raised papule, ulcerates & encrusts dry, raised lesion usually on foot/leg– Satellite lesions hyper-elevate - 10-15 yrs from onset

Chromoblastomycosis – Clinical Manifestations

Chromoblastomycosis

• Laboratory Diagnosis: – Direct Prep: Copper-colored, multiple dividing cells– Three major organisms: Cladosporium, Fonsecaea, Phialophora– Culture = differ by conidial structures– Can be considered dimorphs – yeast-like in vivo, mould in vitro

• Treatment: – Specific antifungals usually ineffective– Itraconazole, terbinafine, or posaconazole– Combined with 5-fluorocytosine in refractory cases

Phaeohyphomycosis• Epidemiology:

– Syndrome caused by more than 20 different saprobes– Fungi appear in tissue as irregular hyphae, not the sclerotic cells seen in

Chromoblastomycosis– Traumatic inoculation

• Clinical syndromes:– Solitary inflammatory cyst– Slow growing (months to years)

• Laboratory Diagnosis:– Surgical excision of cyst = inflammatory cyst with fibrous capsule, necrosis, fungal

elements• Treatment:

– Surgical excision– Itraconazole, posaconazole, voriconazole, terbinafine

Mycetoma

• Epidemiology :– tropical & subtropical– Soil saprobes– Trauma required for inoculation

• Clinical Manifestations: – Not contagious– Swollen deep seated lesion of hand or foot

Mycetoma – Clinical Manifestation

Mycetoma

• Laboratory diagnosis: – Caused by many diverse microbes– Eumycetoma (fungal mycetoma)

• Scedosporium (teleomorph Pseudallescheria)• Resistant to Amphotericin B!

– Actinomycetoma (actinomycotic mycetoma)• Actinomyces, Nocardia, Actinomadura, Streptomyces

• Treatment: – Bacterial – antibiotics– Fungal – surgery and long-term treatment

Subcutaneous Zygomycosis• Epidemiology:

– Africa, India, Latin America– Traumatic implanation

• Conidiobolus coronatus and Basidiobolus ranarum

• Clinical Syndromes:– B. ranarum – large, movable mass localized to shoulder, pelvis, hip and

thigh– C. coronatus – confined to rhinofacial area

• Laboratory diagnosis:– Biopsy = focal clusters of inflammation, eosinophils, zygomycete hyphae

• Treatment:– Itraconazole