Mycology

Superficial Mycoses

surface growth: skin and hair

Pityriasis Versicolor

Associated with pigmentation
Malassezia complex
Observed worldwide (Especially in tropical environments)
Long, pink (gram-negative)

Pityriasis Versicolor: Transmission

Contact with patches

Pityriasis Versicolor: Treatment

Not required -> not dangerous
Rarely resolves on its own
Antifungal ointment or shampoo
“Cosmetic/aesthetic issue”

Tinea Nigra

Hortaea werneckii
Dimorphic (Black mold; Grows as yeast on skin)
Mostly found in the tropics
Usually young adults and children
More common in women than men

Tinea Nigra: Disease

superficial, causes dark pigmentation
looks like patch on skin

Tinea Nigra: Transmission

Unknown!
Patches do not seem to be infectious

Tinea Nigra: Treatment

Not required -> not dangerous
Rarely resolves on its own
Antifungal ointment
“Cosmetic/aesthetic issue”

Black Piedra

Piedraia hortae
Rare (Found in tropical regions )
Associated with poor hygiene

Black Piedra: Disease

unsightly, brown-black nodules on hair strands (gritty)

Black Piedra: Transmission

unknown (not contagious)

Black Piedra: Treatment

removal of hair, hygiene

White Piedra

not dandruff
trichosporon
found in tropical and subtropical regions
associated with poor hygiene

White Piedra: Disease

unsightly, white nodules on hair strands

White Piedra: Transmission

unknown (not contagious)

White Piedra: Treatment

removal of hair
hygiene
antifungal (shampoo)
harder than Black Piedra

Cutaneous Mycoses

invades skin, hair, or nails

Dermatophytosis

different fungi can be the agent of this
Trichophyton
Epidermophyton
Microsporum
spore formation

Dermatophytosis: Disease

break down keratin surfaces (nails)
also can cause ringworm
hair shaft infections

Trichophyton

what is this?

Epidermophyton

what is this?

Microsporum

what is this?

ectothrix

dermatophytosis infection outside hair shaft

endothrix

dermatophytosis infection inside hair shaft

favic

dermatophytosis infection in root of hair

Geophilic Transmission
(dermatophytosis)

soil (environment)
elicits strong immune response--> may clear infection

Zoophilic Transmission
(dermatophytosis)

animals (not humans)
elicits strong immune response--> may clear infection

Anthroponoses Transmission
(dermatophytosis)

human to human
doesn't elicit immune responses--> may cause chronic infections
need treatment

Dermatophytosis: Treatment

problem can occur with location
antifungal (topical and oral)
natural resistance

Subcutaneous Mycoses

"deep skin"

Sporotrichosis

sporothrix schenckii
dimorphic fungus

Dimorphic

grows as mold in environment
grows as yeast on skin/humans

Sporotrichosis: Epidemiology

environmental (soil, vegetation)
animals (armadillo, cats)
geography (Japan, North and South America)

Sporotrichosis: Disease

Primary site of infection- small nodule (may ulcerate)
Secondary site of infection- migration to draining lymph node

Sporotrichosis: Transmission

wound contact with molds
-Environmental: forest work, mining, gardening (STICKS)
-Zoonotic: Armadillos, cats

Sporotrichosis: Treatment

self-limiting (very rare)
Potassium iodide: easy use and access
Antifungals

Sporotrichosis: Prevention

clothing, shoes

Chromoblastomycosis

can be cause by multiple genus/species
"wart like nodules"

Chromoblastomycosis: Epidemiology

Environmental: soil, vegetation
Geography: tropics

Chromoblastomycosis: Disease

slow growing verrucous nodules or plaques
"wart-like"
-worried about secondary infections

Chromoblastomycosis: Transmission

wound contact with molds
-environmental
-wear shoes!

Chromoblastomycosis: Treatment

usually resistant to antifungals by the time it's detected
if untreated: chronic infection and squamous cell carcinoma (cell cycle messed up)

Chromoblastomycosis: Prevention

clothing, shoes
hands, arms, legs, feet

Eumycotic mycetoma

can be caused by multiple genus/species of fungi
"true fungi" infection
-certain bacteria can cause the same disease --> treatment differs based on bacteria

Eumycotic mycetoma: Epidemiology

environmental: soil, vegetation
geography: tropics with low rainfall

Eumycotic mycetoma: Disease

localized, chronic granulomatous tissue infection
destruction of muscle, fascia, and bone

Eumycotic mycetoma: Transmission

wound contact with molds (environmental)

Eumycotic mycetoma: Treatment

resistant to antifungals (may slow spread)
amputation

Eumycotic mycetoma: Prevention

clothing

Subcutaneous entomophthoromycosis

same order (Entomophthorales)
dimorphic
Conidiobolus coronatus
Basidiobolus ranarum

Subcutaneous entomophthoromycosis: Epidemiology

environmental: plant debris
geography: predominantly observed in Africa
- Middle East, Asia, Latin America also

Conidiobolus coronatus: Disease

mostly adults
facial (nasal cavity --> inhalation)

Conidiobolus coronatus: Transmission

inhalation of spores into nasal cavity

Basidiobolus ranarum: Disease

mostly children
appendages (hands and knees primarily)

Basidiobolus ranarum: Transmission

wound contact with mold (crawling increases exposure)

Subcutaneous entomophthoromycosis: Treatment

potassium iodide
antifungals

Subcutaneous entomophthoromycosis: Prevention

avoidance (both)
Masks (Conidiobolus coronatus)
Clothes (Basidiobolus ranarum)

Subcutaneous phaeohyphomycosis

can be cause by multiple genus/species of fungi
infections can range from superficial, subcutaneous, deeply invasive (all three localized) to disseminated (systemic)
-want to diagnose as soon as possible

Subcutaneous phaeohyphomycosis: Epidemiology

soil, wood, and decaying vegetation

Subcutaneous phaeohyphomycosis: Disease

paulonodules, verrucous, cysts, abscesses, hyper keratotic or ulcerated plaques, pyogranuloma, non-healing ulcers or sinuses

Subcutaneous phaeohyphomycosis: Transmission

wound contact with molds
-environmental: warm temp
-exposure, penetration of barrier

Subcutaneous phaeohyphomycosis: Treatment

surgical excision
antifungals
the earlier the better

Subcutaneous phaeohyphomycosis: Prevention

clothing

Systemic Mycoses

whole body
dangerous to immunocompromised (rare)
masks --> prevent respiratory infections
all are dimorphic
Transmission via spore inhalation
dose and immune status major factors for severity
systemic map: know where the areas are higher risk

Blastomycosis

Blastomyces dermatitidis

Blastomycosis: Epidemiology

decaying organic material
United States (MN to east coast minus FL)

Blastomycosis: Disease

primary site of infection: pulmonary disease (

Blastomycosis: Transmission

environment: inhalation
-hits warm of respiratory tract, transformed to yeast, can get past the respiratory tract and become systematic

Blastomycosis: Treatment

antifungal --> if caught early

Blastomycosis: Prevention

avoidance and masks

Coccidioides

Coccidioides (multiple species)

Coccidioides: Epidemiology

desert: enhancement with bat and rodent feces (Mexico and Africa)
South America

Coccidioides: Disease (low dose)

-Make an immune response --> vaccinate themselves
-asymptomatic
-self-limiting pulmonary disease
-protective memory response

Coccidioides: Disease (high dose/"other factors")

-other factors: state of respiratory tract
pulmonary disease: skin, soft tissue, bones, joint, and meninges

Coccidioides: Disease (other)

Immunocompromised: high doses can be lethal
Other factors: ethnicity, age- elderly, gender- higher effect in men, Pregnancy- late or postpartum, hormones play a role

Coccidioides: Transmission

dimorphic
inhalation

Coccidioides: Treatment

antifungals (those with risk factors)
-normally, a healthy individual can fight it off themselves

Coccidioides: Prevention

avoidance, masks

Histoplasmosis

Histoplasmosis capsulati
Histoplasmosis duboisii

Histoplasmosis: Epidemiology

caves, decaying buildings (bat and bird feces)

Histoplasmosis capsulati: Disease

North America
low dose --> asymptomatic
high dose --> pulmonary : systemic-scaring

Histoplasmosis duboisii: Disease

Africa
low dose --> asymptomatic
high dose --> pulmonary : skin and bone

Histoplasmosis: Transmission

inhalation

Histoplasmosis: Treatment

antifungals --> chronic infections
most individuals will be able to fight off

Histoplasmosis: Prevention

avoidance and masks

Paracoccidiodidomycosis

Paracoccidiodidomycosis brasiliensis
dimorphic

Paracoccidiodidomycosis: Epidemiology

Brazil
??? no one knows
soil?

Paracoccidiodidomycosis: Disease

pulmonary infection: inseminate to skin, mucosa, CNS, bones (if untreated)
-ulceration of mouth, lips, gums, and palate
At risk: Children (10-19), Men (30-50)
-estrogen inhibits mold --> yeast transformation
Asymptomatic
-Dormant--> reactivation

Paracoccidiodidomycosis: Transmission

respiratory --> inhalation with humidity
may also include traumatic inculcation (penetration of barrier)

Paracoccidiodidomycosis: Treatment

antifungals
chronic infection --> long term treatment

Paracoccidiodidomycosis: Prevention

avoidance and masks

Talaromycosis

talaromycosis marneffei

Talaromycosis: Epidemiology

south east Asia
??? don't know
bamboo roots? soil?

Talaromycosis: Disease

only in immunocompromised: mimics TB, leishmaniasis, histoplasmosis, cryptococcus (AIDS related opportunistic infections)
-hard to diagnose/detect --> lead to wrong diagnosis --> improper treatment
Pulmonary infection: skin lesions

Talaromycosis: Transmission

unknown because source is unknown (inhalation?)

Talaromycosis: Treatment

antifungals
-difficult to determine when to use if diagnosis is misidentified

Talaromycosis: Prevention

avoidance and masks

Fungi: non-infections

mycotoxins
-exotoxins: produced by certain fungi
-through inhalation, ingestion, or contact
-notable mycotoxins

Alfatoxins: Source

corn, nuts (can be aerosolized)

Alfatoxins: Disease

-carcinogen (activates proto-oncogenes)
-associated with hepatitis and other liver problems