VIII- Fungal SSTI

Question 1

superficial mycoses infections limited to

Answer 1

1. skin (stratum corneum)
2. hair cuticle

cosmetic concern no physical discomfort

Question 2

tinea/pityriasis versicolor cause

Answer 2

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

Question 3

tinea versicolor prez

Answer 3

numerous irreg shaped scaly patches
-yellow/brown color that is hypo or hyper pigmentation
-failure to tan

Question 4

diagnosing tinea versicolor

Answer 4

direct observation of skin scrapings
-spaghetti and meatball appearance with KOH
-may require lipid rich overlay

Question 5

treatment of tinea versicolor

Answer 5

topical treatment to remove orgs from skin with keratolytic agents or azoles (dandruff shampoo)
-change physiology or hygiene issues (grease)

Question 6

tinea nigra cause

Answer 6

exophiala weneckii
-dimorphic

traumatic inoculation but very superficial and minor (soil, sewage, wood, compost)

Question 7

tinea nigra prez

Answer 7

distinct oval shaped lesions on hands and feet
-light brown/black color from melanin production

Question 8

tinea nigra diagnosis

Answer 8

KOH prep shows skin scrapings with two cell yeast and dark pigments

Question 9

black piedra cause

Answer 9

piedra hortae
-tropics, soil, stagnant water, vegetation

Question 10

white piedra cause

Answer 10

trichosporon beigelii
-soil and decaying vegetation
-contact with infected animals

Question 11

black piedra prez

Answer 11

hard gritty black/brown nodules on hair primarily scalp
-firmly attached

Question 12

white piedra prez

Answer 12

soft nodules white/light brown on pubic or axillary hair, beards, eyebrows
-loosely attached

Question 13

piedra treatment

Answer 13

shaving off hair + good hygiene

Question 14

cutaneous mycoses infections limited to

Answer 14

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

Question 15

tinea capitis

Answer 15

@ scalp, eyebrows, lashes
T. tonsurans

Question 16

tinea pedis prez

Answer 16

aka athletes foot
@ toe webs but also heels, sides foot, nails
-chronic infection
-can have pustules (may indicate bacterial superinfection)

Question 17

tinea corporis

Answer 17

aka ringworm @torso, arms, legs
-erythematous, round, scaly raised border

Question 18

agents of cutaneous infections

tineas

Answer 18

1. microsporum
2. trichophyton
3. epidermophyton

Question 19

dermatophytes growth in hair

Answer 19

1. extothrix - surrounds hair shaft
2. endothrix - inside hair

Question 20

tinea cruris prez

Answer 20

aka jock itch
-dry erythematous lesion in groin of men
-not infect penis and scrotum

Question 21

tinea unguium-onychomycosis

Answer 21

infect nail bed and nail plate
-hyperkeratosis and discoloration, dry, cracked, brittle
-esp diabetic and AIDS

can also be caused by C. albicans

Question 22

diagnosing dermatophytic infections

Answer 22

-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

Question 23

treating dermatophyte infections

Answer 23

apply exfoliating agents + topical azoles
-griseofulvin for tinea capitis
-tinea unguium very diff to treat, need long term oral antifungal

Question 24

cutaneous candidiasis prez

Answer 24

@ body folds or frequently moist areas
-diaper rashes, dishwashers hands

papules or confluent plaques that are red, tender, cracked
-also nail infections

Question 25

chronic mucotaneous candidiasis

Answer 25

@ mouth, skin, finger nails -associated with T cell deficits and endocrine disorders -granulomatous resp = disfigurement and discomfort

Question 26

factors of disseminated candidiasis

Answer 26

1. inc colonization (disrupt normal flora) 2. breakdown of physical barriers 3. immune suppression

Question 27

candida auris problem

Answer 27

-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

Question 28

subcutaneous infections limited to

Answer 28

dermis, subcutaneous tissue, bone -traumatic inoculation

Question 29

subcutaneous agents

Answer 29

1. sporotrichosis 2. chromoblastomycosis 3. mycetoma fungal

Question 30

sporotrichosis cause

Answer 30

*sporothrix schenckii* (dimorphic) -in rose thorns, wood splinters, sphagnum moss -cigar shaped yeast in tissue

Question 31

sporotrichosis prez

Answer 31

inflamm > painless granulomatous lesion > ulcerate > secondary lesions along lymphatic tract

Question 32

diagnosing sporotrichosis

Answer 32

cultivate from tissue or pus -mold converts to yeast at 37 degrees

Question 33

treating sporotrichosis

Answer 33

oral potassium iodide

Question 34

chromoblastomycosis cause

Answer 34

traumatic inoculation by Cladosporium or Phialophora

Question 35

chromoblastomycosis prez

Answer 35

lesions @ leg or food wart like > large scaly red lesions that look like cauliflower -painless

Question 36

diagnosing chromoblastomycosis

Answer 36

brown pigmented hyphae in skin scrapings + copper colored spherical cells (medlar bodies) aka look like pennies = replicating form

Question 37

fungal mycetoma cause

Answer 37

warmer tropical climates soil inhabiting fungi -madurella mycetomatis, grisea -pseudallescheria boydii | aka madura foot

Question 38

fungal mycetoma prez

Answer 38

slow growing papule > ulcer = pus and blood -draining tracts or sinuses develop -underlying bone gets involved = pitted lesions

Question 39

diagnosing mycetoma

Answer 39

direct observe colored grains in pus, tissue, discharge -compacted hyphae and conidia