Fungus and fungal infection I Flashcards
- Pityriasis versicolor
- Tinea niagra
- Black piedra
- White piedra
What are the conditions caused by Superficial mycoses?
- Caused by Malassezia furfur
- Superficial infection of the stratum corneum - interfere with melanin production
- Appeared as hypopigmented macular lesions often associated with slight scaling or itching
Pityriasis versicolor
- caused by Exophiala werneckii
- a well-demarcated brown-black macular lesion
- most commonly seen on palms and soles
Tinea nigra
- superficial infection of the hair
- caused by Piedraia hortae
- infection of shaft of hairs of beard and scalp
Black piedra
- infection of the hair
- caused by yeast-like organism Trichosporon beigelli
- development of a soft, pasty, cream-colored growth along infected hair shaft
White piedra
- Disease of the skin, hair, and nail
- caused by a group of closely related fungi known as dermatophytes
Cutaneous mycoses
Tricophyton
Hair, skin, and nail
Microsporum
Hair and skin
Epidermophyton
Skin and nail
- skin, nail, and hair
- mostly elongate, pencil shaped with micronidia
Trichophyton spp
- skin and hair
- easily identified on the scalp
- the loose, cottony mycelia produce macroconidia which are thick-walled and spindle-shaped
- infected hairs fluorescence a bright green colour when illuminated with a UV-emitting Wood’s light
Microsporum spp
- skin and nails
- readily identified by the thick, bifurcated hyphae with multiple smooth, club-shaped, macroconidia
Epidermophyton spp
Tinea means ringworm or moth-like. What are the names of the 8 Tinea infections?
- capitis (head)
- faciei (face)
- barbae (beard)
- corporis (body)
- cruris (groin)
- manuum (hand)
- unguium (nail)
- pedis (foot)
- scalp and hair
- found in children
- dull gray, circular patches of alopecia, scarring, and itching
Tinea capitis
- ringworm of the bearded areas of the face and neck
- also known as barber’s itch
- follicular inflammation or as cutaneous granulomatous lesion
Tinea barbae
- small annular ring lesions with scaly centre occurring anywhere on the body
- inflamed circular border containing papules and vesicles surrounding a clear area of relatively normal skin
- the periphery of the ring which is the site of active fungal growth is inflamed and vesiculated
- the lesions are typically pruritic
Tinea corporis
- groin, perineum, or perianal area
- can spread from the upper thigh to the genitals
Tinea cruris (jock itch)
- nails are thickened, broken, discolored, and brittle
- clipped nail used for culture
- treatment must be continued for 3 to 4 months until all the infected portions of the nail grow out and are trimmed off
Tinea unguium
- infected tissue is initially between the toes but can spread to the nails which become yellow and brittle
- caused by Trichophyton spp or Epidermophyton floccosum
- skin fissures can lead to secondary bacterial infection
Tinea pedis (athlete’s foot)
Treatment for Tinea capitis, corporis, pedis, and unguium
Tinea capitis: terbinafine, topical antifungal
Tinea corporis, pedis: terbinafine and itraconazole
Tinea unguium: terbinafine or itraconazole
infection of the dermis, subcutaneous tissue, muscle, and fascia
subcutaneous mycoses
- mycetoma
- chromoblastomycosis
- phaeohyphomycosis
- sporotrichosis
- rhinosporidiosis
infections of subcutaneous mycoses
- slowly progressive, chronic granulomatous infection of skin and subcutaneous tissues
- involvement of underlying fascia and bone
- caused by a number of actinomycetes and filamentous fungi
- enter through penetrating injuries resulting from thorn pricks, splinters, etc.
- microabcesses burst open with the formation of chronic multiple sinuses discharging copious, seropurulent fluid containing granules
- the color and consistency of these granules vary depending on the fungi that cause the disease
mycetoma
- slowly progressing granulomatous infection caused by several soil fungi
- dematiaceous fungi: brown to black melanin pigment in their cell wall and their conidia or hyphae are dark coloured - grey or black
- lesion vegetate and develop to a cauliflower-like lesion
chromoblastomycosis
- heterogeneous group of cutaneous diseases caused by various dematiaceous fungi
- diagnosis is made by demonstration of darkly pigmented, septate hypahe
- solitary encapsulated cysts in the subcutaneous tissue to sinusitis to brain abcesses
phaeohyphomycosis
- chronic pyogenic granulomatous lesion of the skin and subcutaneous tissue caused by sporothrix schenckii
- introduced in skin by sporathrix lives in soil and on plant matter such as sphagnum moss, rose bushes, and hay through a penetration of thorn
- causes a local pustule or ulcer with the nodules along the draining lymphatic vessels
sporotrichosis (rose garderner’s disease)
- chronic granulomatous disease caused by rhinosporidium seeberi
- characterized by the development of large friable polyps or wart-like lesion in the nose, conjunctiva, or eye
- occasionally seen in ears, larynx, bronchus, urethra, vagina, rectum, and skin
- transmitted by dust and water
- infection in persons taking bath in stagnant pool and in individuals who dive in streams to collect sand from river beds
rhinosporidiosis
- coccidioidomycosis
- paracoccidioidomycosis
- histoplasmosis
- blastomycosis
infections are initiated in the lungs, following inhalation of the respective conidia
systemic mycoses
- caused by coccidioides immitis or coccidioides posadasii
- progressive pulmonary infection and dissemination: skin, bone, joints, and meninges in immunocompromised patients
- found in soil and the growth of the fungus in the environment is enhanced by bat and rodent droppings
coccidioidomycosis
- caused by paracoccidioides brasiliensis
- occurs in young people as a self-limited pulmonary process
- reactivation of a primary quiescent lesion may occur years later, resulting in chronic progressive pulmonary disease
- high humidity, rich vegetation, moderate temperatures and acid soil
paracoccidioidomycosis
- a disease of reticuloendothelial system caused by an intracellular fungus histoplasma capsulatum
- soil with high nitrogen content (bird/bat droppings)
- acute pulmonary histoplasmosis
- disseminated disease in immunocompromised host and in children
- splunkers disease
- flu-like illness, fever, headache, non-productive cough
- if untreated, the disseminated form of disease is usually fatal
- shortness of breath, productive cough, sputum purulent or bloody, anorexic, lose weight, night sweats, like Tb
histoplasmosis
- caused by blastomyces dermatitidis
- pulmonary disease
- extrapulmonary dissemination in immunocompromised patients: skin, bone, genitourinary, CNS
- decaying organic matter (soil and leaf litter)
blastomycosis