VIII- Fungal SSTI Flashcards
superficial mycoses infections limited to
- skin (stratum corneum)
- hair cuticle
cosmetic concern no physical discomfort
tinea/pityriasis versicolor cause
Malassezia furfur (pityrosporum orbiculare)
-dimorphic and part of normal microbiota esp lipophillic areas (rich sebaceous glands)
environmental factors promote growth in hyphal phase so inc lipid/grease production or moist heat
tinea versicolor prez
numerous irreg shaped scaly patches
-yellow/brown color that is hypo or hyper pigmentation
-failure to tan
diagnosing tinea versicolor
direct observation of skin scrapings
-spaghetti and meatball appearance with KOH
-may require lipid rich overlay
treatment of tinea versicolor
topical treatment to remove orgs from skin with keratolytic agents or azoles (dandruff shampoo)
-change physiology or hygiene issues (grease)
tinea nigra cause
exophiala weneckii
-dimorphic
traumatic inoculation but very superficial and minor (soil, sewage, wood, compost)
tinea nigra prez
distinct oval shaped lesions on hands and feet
-light brown/black color from melanin production
tinea nigra diagnosis
KOH prep shows skin scrapings with two cell yeast and dark pigments
black piedra cause
piedra hortae
-tropics, soil, stagnant water, vegetation
white piedra cause
trichosporon beigelii
-soil and decaying vegetation
-contact with infected animals
black piedra prez
hard gritty black/brown nodules on hair primarily scalp
-firmly attached
white piedra prez
soft nodules white/light brown on pubic or axillary hair, beards, eyebrows
-loosely attached
piedra treatment
shaving off hair + good hygiene
cutaneous mycoses infections limited to
keratinized layers, epidermis, dermis of skin, nails, hair
-bc dermatophytes capable of degrading keratin for nutrients
-since deeper tissue will induce inflamm or allergic inflamm
tinea capitis
@ scalp, eyebrows, lashes
T. tonsurans
tinea pedis prez
aka athletes foot
@ toe webs but also heels, sides foot, nails
-chronic infection
-can have pustules (may indicate bacterial superinfection)
tinea corporis
aka ringworm @torso, arms, legs
-erythematous, round, scaly raised border
agents of cutaneous infections
tineas
- microsporum
- trichophyton
- epidermophyton
dermatophytes growth in hair
- extothrix - surrounds hair shaft
- endothrix - inside hair
tinea cruris prez
aka jock itch
-dry erythematous lesion in groin of men
-not infect penis and scrotum
tinea unguium-onychomycosis
infect nail bed and nail plate
-hyperkeratosis and discoloration, dry, cracked, brittle
-esp diabetic and AIDS
can also be caused by C. albicans
diagnosing dermatophytic infections
-determine source i.e. pets + confirm differential (diff from candida, viral, bacterial) + anticipate resp to therapy
KOH prep of skin scrapings/nail/hair samples to confirm if fungal but not agent
UV wood lamps!! for scalp or beard hairs that fluoresce
treating dermatophyte infections
apply exfoliating agents + topical azoles
-griseofulvin for tinea capitis
-tinea unguium very diff to treat, need long term oral antifungal
cutaneous candidiasis prez
@ body folds or frequently moist areas
-diaper rashes, dishwashers hands
papules or confluent plaques that are red, tender, cracked
-also nail infections
chronic mucotaneous candidiasis
@ mouth, skin, finger nails
-associated with T cell deficits and endocrine disorders
-granulomatous resp = disfigurement and discomfort
factors of disseminated candidiasis
- inc colonization (disrupt normal flora)
- breakdown of physical barriers
- immune suppression
candida auris problem
-drug resistant to like everything except echinocandins but super expensive
-in patients with underlying medical conditions, antibiotic use, prolonged hospitalization
-blood stream infections and high mortality rate
subcutaneous infections limited to
dermis, subcutaneous tissue, bone
-traumatic inoculation
subcutaneous agents
- sporotrichosis
- chromoblastomycosis
- mycetoma fungal
sporotrichosis cause
sporothrix schenckii (dimorphic)
-in rose thorns, wood splinters, sphagnum moss
-cigar shaped yeast in tissue
sporotrichosis prez
inflamm > painless granulomatous lesion > ulcerate > secondary lesions along lymphatic tract
diagnosing sporotrichosis
cultivate from tissue or pus
-mold converts to yeast at 37 degrees
treating sporotrichosis
oral potassium iodide
chromoblastomycosis cause
traumatic inoculation by Cladosporium or Phialophora
chromoblastomycosis prez
lesions @ leg or food
wart like > large scaly red lesions that look like cauliflower
-painless
diagnosing chromoblastomycosis
brown pigmented hyphae in skin scrapings + copper colored spherical cells (medlar bodies) aka look like pennies = replicating form
fungal mycetoma cause
warmer tropical climates soil inhabiting fungi
-madurella mycetomatis, grisea
-pseudallescheria boydii
aka madura foot
fungal mycetoma prez
slow growing papule > ulcer = pus and blood
-draining tracts or sinuses develop
-underlying bone gets involved = pitted lesions
diagnosing mycetoma
direct observe colored grains in pus, tissue, discharge
-compacted hyphae and conidia
