Jarrod Fortwendel, PhD
Department of Microbiology and Immunology [email protected]
MSB 2142
Nov. 18-22, 2013

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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

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Infections of the skin, hair, nail
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Invades keratinized layers
Tinea – latin for “worm”
Subgroups of infections
1. Dermatophytoses – “classical ringworm”
2. Non-dermatophytic cutaneous mycoses…
“the other superficial group”

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

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Epidemiology
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Anthropophilic, zoophilic, geophilic
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Transmissible
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Invade skin, hair and nails
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Collectively called “tinea”
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3 major Genera:
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Trichophyton
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Epidermophyton
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Microsporum
T. rubrum
T. mentagrophytes
Cause 80-90% of cases worldwide

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Virulence factors and pathogenesis:
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Infectious element
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Arthroconidia
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Keratin utilization
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Keratinophilic and keratinolytic
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Hair invasion/colonization
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Endothrix, Ectothrix, Favic

Clinical: Classified by anatomical site affected
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Tinea capitis
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Microsporum spp. –
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M. audouinii,
gray patch ringworm
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M. canis, M. gypseum
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Tinea corporis – point lesion
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centrifugal spread –
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anywhere on body from eyebrow and neck “southward”
Trichophyton spp., Epidermophyton, (Also Candida)
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Tinea pedis
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cosmopolitan
Trichophyton spp., Epidermophyton
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Tinea unguium
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Often as a secondary infected site
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Almost any dermatophyte, esp Trichophyton rubrum, (Also Candida)

Tinea capitis

Tinea corporis

Tinea imbricata
Etiology: Trichophyton concentricum

Tinea cruris

Tinea cruris

Tinea unguium - onychomycosis

Tinea barbae

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

Tinea pedis

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Requires demonstrating hyphae/arthroconidia from skin, hair, nails
Direct preparation:
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Lesion scrapings/hair examined by calcofluor/KOH
Alternatively - Wood’s Light:
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UV irradiation of infected hair, false positive/negative
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Report: Hyphal fragments/arthrocondida seen
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Culture: SDA +; SDA-CC +
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LPCB

Direct KOH prep: Hyphal fragments seen http://www.mycology.adelaide.edu.au/virtual/2009/ID2-Oct09.html

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

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Localized cutaneous - topical agents
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Clotrimazole (Lotrimim), Miconazole (micatin)
Tolnaftate (tinactin), terbinafine (lamisil)
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Hair, nails – oral therapy
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Fluconazole, itraconazole, griseofulvin
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Griseofulvin
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Concentrates in newly keratinized layers of cells
Virtually eradicated epidemic tinea capitis; used in tinea unguium and extensive infections.
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Recurrences are common

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Candida spp.
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Fluconazole
Scopulariopsis spp.
Scytalidium spp.
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partial surgical nail removal + antifungal
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**Possible other nail pathogens:
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Aspergillus spp.
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Fusarium spp.
Acremonium spp.
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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**

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Wood Light – positive
Skin biopsy
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Enterococcus spp. and Trichophyton tonsurans
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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

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Tinea versicolor – AKA pityriasis versicolor
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Malessezia furfur
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Tinea nigra palmaris
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Hortaea (Exophiala) werneckii
Piedra – black
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Piedraia hortai
Piedra – white
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Trichosporon beigelii

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Tinea versicolor – AKA pityriasis versicolor
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Malessezia furfur
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Very common – up to 60% infected population in certain tropical environments
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Most common in tropic and subtropics
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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
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Little-to-no host immune reaction

Chest
Back

“Spaghetti and meatballs”
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Diagnosis made by direct exam
Does not culture routinely - lipophilic
Treatment: 2.5 % Selenium sulfide or topical cream azoles
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Severe cases: Oral ketoconazole
“collarette”

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Tinea versicolor – AKA pityriasis versicolor
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Malessezia furfur
Tinea nigra
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Hortaea (Exophiala) werneckii
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Piedra – black
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Piedraia hortai
Piedra – white
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Trichosporon beigelii

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Tinea versicolor – AKA pityriasis versicolor
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Malessezia furfur
Tinea nigra
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Hortaea (Exophiala) werneckii
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Superficial phaeohyphomycosis
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Solitary, irregular, pigmented macule usually on palms or soles
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Tropic or subtropic
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Traumatic inoculation
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Not contagious
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Can resemble a malignant melanoma

2. Culture = dematiaceous, yeast-like colony in 3 weeks
4. Treatment:
Topical azoles
1. KOH prep = pigmented hyphae and yeast http://www.mycology.adelaide.edu.au/virtual/2007/ID2-Feb07.html
3. Microscopic
= two-celled, cylindrical, yeast-like cells http://www.mycology.adelaide.edu.au/virtual/2007/ID2-Feb07.html

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Tinea versicolor – AKA pityriasis versicolor
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Malessezia furfur
Tinea nigra palmaris
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Hortaea (Exophiala) werneckii
Piedra – black
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Piedraia hortae
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Piedra – white
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Trichosporon beigelii

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Tinea versicolor – AKA pityriasis versicolor
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Malessezia furfur
Tinea nigra palmaris
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Hortaea (Exophiala) werneckii
Piedra – black
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Piedraia hortae
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Tropical, poor hygiene, uncommon
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Small, dark nodules surrounding hair shaft
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Clumped together by cement-like substance with asci and ascospores
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Diagnosis = direct exam
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Treatment = haircut, washing

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Tinea versicolor – AKA pityriasis versicolor
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Malessezia furfur
Tinea nigra palmaris
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Hortaea (Exophiala) werneckii
Piedra – black
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Piedraia hortai
Piedra – white
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Trichosporon beigelii
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Tropical and subtropical, poor hygiene
Affects hairs of groin and axillae
Forms soft, white/brown swelling on hair shaft
Shaving and washing

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Tinea versicolor – AKA pityriasis versicolor
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Malessezia furfur
Tinea nigra palmaris
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Hortaea (Exophiala) werneckii
Piedra – black
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Piedraia hortai
Piedra – white
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Trichosporon beigelii
Other non-dermatophytic (several)
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E.g. Candida, Fusarium, and more…

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AKA: Inoculation Mycoses – normal soil inhabitants
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Primary infection in deep skin, muscle or connective tissue
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Slowly progressive and chronic, usually confined
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Not transmissible
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Subgroups of subcutaneous mycoses
I.
Sporotrichosis
II.
III.
IV.
Chromoblastomycosis/Phaeohyphomycosis
Mycetoma
Subcutaneous Zygomycosis

Sporotrichosis – Sporothrix schenkii
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Epidemiology :
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Decaying vegetation, esp used for mulching
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Enters via splinters, thorn pricks
-Occupational hazard
Clinical Aspects:
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Primary nodular lesion
 necrotic ulcer, suppurative
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Proximal lymphatics may chronically infect (dissemination rare)
Sporothrix schenckii:
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Direct prep: RARE blastoconidia
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Sporothrix is a thermal dimorph
At RT: DEMATIACEOUS colony, HYALINE septate hyphae, delicate lateral conidiophores w/ delicate rosettes of conidia
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At 37°C in vivo & in vitro: oval, cigar-shaped blastoconidia.
Treatment:
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Itraconazole

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Epidemiology:
– tropics – PR, Cuba, Costa Rica and Brazil
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Soil saprobes; dematiaceous fungi
Trauma is required, occurs when shoes are rarely worn
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Clinical Manifestations:
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Not contagious
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Incubation unknown
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Chronic skin and subcutaneous infections
Small raised papule, ulcerates & encrusts
 dry, raised lesion usually on foot/leg
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Satellite lesions hyper-elevate - 10-15 yrs from onset

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Laboratory Diagnosis:
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Direct Prep: Copper-colored, multiple dividing cells
Three major organisms: Cladosporium, Fonsecaea, Phialophora
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Culture = differ by conidial structures
Can be considered dimorphs – yeast-like in vivo, mould in vitro
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Treatment:
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Specific antifungals usually ineffective
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Itraconazole, terbinafine, or posaconazole
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Combined with 5-fluorocytosine in refractory cases

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Epidemiology:
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Syndrome caused by more than 20 different saprobes
Fungi appear in tissue as irregular hyphae, not the sclerotic cells seen in Chromoblastomycosis
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Traumatic inoculation
Clinical syndromes:
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Solitary inflammatory cyst
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Slow growing (months to years)
Laboratory Diagnosis:
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Surgical excision of cyst = inflammatory cyst with fibrous capsule, necrosis, fungal elements
Treatment:
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Surgical excision
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Itraconazole, posaconazole, voriconazole, terbinafine

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Epidemiology :
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– tropical & subtropical
Soil saprobes
Trauma required for inoculation
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Clinical Manifestations:
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Not contagious
Swollen deep seated lesion of hand or foot

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Laboratory diagnosis:
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Caused by many diverse microbes
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Eumycetoma (fungal mycetoma)
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Scedosporium (teleomorph Pseudallescheria)
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Resistant to Amphotericin B!
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Actinomycetoma (actinomycotic mycetoma)
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Actinomyces, Nocardia, Actinomadura, Streptomyces
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Treatment:
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Bacterial – antibiotics
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Fungal – surgery and long-term treatment

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Epidemiology:
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Africa, India, Latin America
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Traumatic implanation
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Conidiobolus coronatus and Basidiobolus ranarum
Clinical Syndromes:
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B. ranarum – large, movable mass localized to shoulder, pelvis, hip and thigh
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C. coronatus – confined to rhinofacial area
Laboratory diagnosis:
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Biopsy = focal clusters of inflammation, eosinophils, zygomycete hyphae
Treatment:
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Itraconazole