Genital Disorders and Fungal Skin Infections Flashcards
Describe yeast
Typically round and reproduce by budding.
Species: Candida spp. or Cryptococcus neoforms
Describe dimorphic fungi.
Can grow as yeast at higher temperatures and wold aat lower temperatures.
Species: Histoplasma, capsultaum, blastomyces, dermatitids, coccidioides immitis
Describe mold
Grow as multicellular tubular structures called hyphae that branch.
Species: Aspergillus spp. and dermatophytes (cause infection in humans and animals)
Dermatophytes–> Trichophyton, Microsporum, Nannizzia, Epidermophyton
What are the primary sources of infection for dermatophytes?
- Anthropophilic- natural pathogens of humans
- Geophilic- originates from soil
- Zoophilic- primarily an animal pathogen
What is the most common anthropophilic species?
T. rubrum
Most common cause of human infections
What is the most common geophilic species?
N. gypseum
Uncommon cause of humas infections
What is the most common zoophilic species?
M. canis (primary source: cats and dogs)
How are dermatophyte infections transmitted?
- Symptoms typically start 4-14 days after exposure.
Transmission
* Direct skin contact with infected animals or people
* Sharing personal items (clothes, bedding, towels, combs
* Contact with moist surfaces (shower or locker room)
How are dermatophyte infections named?
- Tinea capitis (scalp)
- Tinea corporis (trunk or legs)
- Tinea cruris (groin)
- Tinea pedis (feet)
What tests do we use to detect dermatophyte infections?
KOH preparation process
1. Collect a scraping from infected area and place on slide
2. Add KOH to the slide
3. Visualize under the microscope
KOH dissolves skin cells and leaves fungal elements behind for visualization.
Other method: culture
Describe tinea corporis fungal infections.
Clinical presentation
* Legions with a prominent edge typically on the trunk and legs
* The center is often less inflamed
* Called ringworm due to sometimes having a ring shape
Symptoms
* Itching
* Papules (bumps)
* Scaly
Epidemiology
* More common in tropical climates
Risks
* Sharing personal items
Causative pathogens
* T. rubrum
* M. canis
Describe tinea capitis fungal infections.
Clinical presentation
* Scaling of the scalp
* Variable amounts of erythema, inflammation, and alopecia
* Also called scalp ringworm
Symptoms
* Itching
* Alopecia (hair loss)
Epidemiology
* Most common in children
Risks
* Sharing personal items
Causative pathogens
* T. tonsurans
Describe tinea cruris fungal infections.
Clinical Presentation
* Starts with irritation in the groin
* Rash can spread to inner thighs, buttocks, and waste
* Also called jock itch
Symptoms
* Itching
Epidemiology
* Most common in young men but can impact women
Risks
* Not changing underwear daily
Causative pathogens
* T. rubrum
* E. floccosum
Describe tinea pedis fungal infections.
Clinical presentation
* Infection starts between toes or under toes
* Can spread to top or bottom of the foot
* Athlete’s foot= scaling between toes
Symptoms
* Itching
* Cracking skin
* Blisters
Epidemiology
* Typically occurs in young adults or teens
Risks:
* Sharing personal belongings
* Wearing tight shoes and socks
* Barefoot in public bathing areas
Causative pathogens
* T. rubrum
* T. interdigitale
Describe onychomycosis fungal infections.
Clinical presentation
* Fungal infection of the nails
* Typically spreads to the nail from adjacent skin
Symptoms
* thickening of the nail
* Nail discoloration (can turn yellow, white, or brown)
Epidemiology
* More common with increasing age
Risks
* Sharing personal iteams
* Wearing tight shoes and socks
* Adjacent dermatophyte infection
Causative pathogens
* T. rubrum
* T. mentagrophytes