Fungal Infections

Question 0

6 types of candidiasis

Answer 0

1. generalized cutaneous
2. intertrigo
3. metastatic skin lesions
4. candida folliculitis
5. paronychia and onychomycosis
6. chronic mucocutaneous candidiasis

Question 1

4th most commonly isolated pathogen in systemic infection

Answer 1

candidia

Question 2

3 facts about cadida

Answer 2

adhere well to organisms/cells
have proteases and phospolipids that penetrate and damage cell
can convert to hyphal form “phenotypic switching”

Question 3

candida is a fungi/yeast? where does it come from

Answer 3

animal->human or in hospital envionments

it is a yeast like fungi

Question 4

what does candida attack?

Answer 4

host with defect: here are examples:
intact mucocutaneous barriers: wound/iv catheter/burn/ulcer
phagocytic cell:granulocytopenia (increased WBC)
*polymorphonuclear leukocytes-chronic granulomatous disease
monocytic cells-myeloperoxidase deficiency
immunoglobins-hypocomplementemia
cell mediated immunity-chrinuc mucocutaneous candidasis, diabetes mellitus, cyclosporin A, corticosteroids, hiv
mucocutaneous protective bacterial florae-broad spectrum antibiotics

Question 5

presentation for generalized cutaneous

Answer 5

itchy, diffuse eruption on trunk, extremities

Question 6

presentation for intertrigo

Answer 6

vesiculopustules in folds and macerations and fissures
scalloped border with white rim consisting of necrotic epidermis
this urrounds red macerated base
satellite lesions
similar to nappy rash

Question 7

metastatic skin lesions occur in how many cadidiasis cases?

Answer 7

about 10%

Question 8

candidia folliculitis presents as

Answer 8

candida in hair follicles

Question 9

paronychia and onychomycosis present as

Answer 9

loss or damage to nail, from immersing hands in water or diabetes mellitus, warm inflammation, tense, glistening, red

Question 10

chronic mucocutaneous candidiasis presents as

Answer 10

between infant-less then 30 years of age; young ppl or HIV positive
persistent!! disfiguring of face, scalp, hands, nails
oral thrush and vitiligo (blotchy loss of skin color)
associated endocrinologies (hyperparathyroidism,hypothyroidism, addisons disease, DM, auto immune antibodies to gastric tissues*, adrenal, thyroid, Tymomas, dental dysplsia, polyglandular auto immune disease, antibodies to melanin producing cells

Question 11

candidiasis overall presentation

Answer 11

occurs in women, HIV pts, young people
on torso, extremities, trunk, hair follicles
50% oral colonization
most of us have in fecal
75% of women get it at least 1 time
disease of skin and mucousal membrane of GI GU and respiratory tract

Question 12

systemic risk factors of candidiasis

Answer 12

*granulocytopenia, bonemarrow transplant, parenternal hyperalimentation, hemotologic malignancies, foley catheter, recent bacterial infection, recent surgery, gi surgery, long hospital stay, severe trauma, burns, acute renal failure, mechanical ventilation more then 3 days, premature birth, broad spectrum ABx, hemodialysis, corticosteroids, chemo radiation, solid neoplasms

Question 13

Etiology of candidiasis

Answer 13

6 major:

1. C. albicans (50-60%)
2. C. glabrata -20% are resistant to fluconazol
3. C. parapsilosis -vascular catheters
4. C. tropicalis - in pts with leukemia and bone marrow transplant
5. C. Krusei -intrinsically resistant to ketoconazole, fluconazole and less susceptible to ampotercin B
6. C. Lusitanial -intrinsically resistant to amphotercin B

Question 14

work up candidiasis

Answer 14

mucocutaneous candidiasis:
wetmount / microscope for hyphae, cysts, pseudohyphae, budding yeast cells
KOH prep/gramstain/methylene blue
Culture nail/hair to make sure you are treating the right thing because its a long treatment!

Question 15

DDx candidiasis

Answer 15

bacterial sepsis, abdominal abscess, asperigillosis

Question 16

list general tx for candidiasis

Answer 16

1. azole antifungals - effect cell membrane
2. glucan synthesis inhibitors- effect cell wall
3. polyenes - effect cytoplasmic membrane
4. allylamine -effect cell wall

Question 17

more depth tx of candidiasis

Answer 17

1. azole antifungals (good for thrush and yeast infection)
   type 1: triazoles (3 atoms in ring): fluconazole, itraconzaole, econazole, terconazole, butoconazole, tioconazole
   tyle 2: imidazoles (2 atoms in ring):miconazole, ketoconazole, clotrimazole
2. glucan synthesis inhibitors (less adverse effects/new): caspofungi, micafungi, anidulafungi
3. polyenes (broad spectrum)-nystatin (mycostatin), amphotericin B, lipid formulations
4. allylamines- less sideeffects! - Terbinafine (daskil, lamisil)

Question 18

list dermatophyte infections

Answer 18

dermatophytosis
pityriasis versicolor/tinea versicolor
onychomycosis

Question 19

list types of dermatophytosis

Answer 19

tinea: capitis (scalp) corporis (trunk) manuum/pedi (palm,sole) cruris (groin) barbae(beard) facial (face) unguium (nail)

Question 20

risk factors for dermatophytosis

Answer 20

moist conditions, communal baths, immunocompromised states, cushing syndrom, athletic activity, atopy, genetic predisposition

Question 21

dermatophytosis presentation

Answer 21

about 2 weeks from inoculation to see skin changes
itching!!
ID rxns*
ring worm look* (spreads out while center starts to heal)
demarcated*
hair loss (if capitis) brittle hair
exposure to sports-judo karate wrestling etc

Question 22

3 common causes of dermatophytosis

Answer 22

1. T. tonsurans
2. M. canis
3. T. rumbrum**

Question 23

hair invasions (tinea capitis) by spore formation (3)

Answer 23

1. ectothrix (conidia form on exterior hair shaft and destroy cuticle)
   a. microsporums - light up with wood light
   b. trichophyton - doesnt light up with wood light
2. endothrix (conidia are inside hair shaft and cuticle is not effected)
   c. trichophyton - doesnt light up with wood light

Question 24

etiology dermatophytosis

Answer 24

ectothrix spps
endothrix spps
favus spps (in and around hair shaft) - honey combed ** destruction of follicle by Trichophyton schoenlenii
kerion-(thick boggy, spongy plaque/ like seborrehic derm but not inflammed) from bacterial infection- microsporum canis
lupod sycosis/sycosis barbae (barber itch) like kerion- chronic stubborn bacterial infection (impetigo) or folliculitis causing follicular scarring **looks like discoid lupus - **hair areas are more prone to disruptive forms of tinea

Question 25

dermatophytosis work up

Answer 25

1. direct microscopic examination KOH (scrape skin hiar nails and treat with KOH prep - look for hyphae on skin and nails and spores on hair)
2. Fungal Culture to ID spps (long tx if wrong)
3. wood light examination to diagnose tinea capitis: microsporum audouinni and m. canis will light up but trichophytan schoeleinii wont

Question 26

dermatophytosis ddx

Answer 26

nummular
seborrheic derm
syphillis
impetgo- bacterial infection
alopecia

Question 27

dermatophytosis tx

Answer 27

1. if tinea sorporis:topical ointment and oral antifungals if stubborn case
2. if tinea capitis or nail: oral antimycotic drug (topical wont work) must get baseline LFT * checks - check half way thu 3 month tx course - if its a kid get a culture because its a long tx for them as oral
3. medication: effects cell wall:
   azoles and allylamine

Question 28

tinea versicolor/pityriasis versicolor presentation

Answer 28

hypo/hyper (hypo is more common) pigmented macules that do not tan
noticed in summer after no symptoms-tan turns u spotty
not usually contagious
superficial and effects melanin

Question 29

tinea versicolor etiology

Answer 29

M. furfur yeast on human skin

grows in seborrheic areas (scalp face chest)

Question 30

tinea versicolor work up

Answer 30

koh prep (spaghetti and meatballs)

Question 31

tinea versicolor ddx

Answer 31

seborrheic derm, tinea corporis, psoriasis guttate

Question 32

tinea versicolor tx

Answer 32

1. selenium sulfide shampoo (neck-waste 15 min-7 days)
2. ketoconazole oral pill (dont shower for 18 hours u will sweat it out)
3. new imidazole cream/lotions $$$$

Question 33

onychomycosis definition

Answer 33

fungal infection of nail

Question 34

6 types of onychomycosis

Answer 34

1. distal lateral
2. endoyx
3. white superficial
4. proximal subungual
5. total dystrophic
6. candidia

Question 35

presentation of each of the 6 types of onychomycosis

Answer 35

1. distal lateral-subungual hyperkeratosis and detachment (onycholysis) yellow/white & painful
2. endoyx -milky white nail plate but not damage/detachment to nail
3. white superficial -small, white, speckled/powdery patches on surface of nail & roughened nail crumbles easily
4. proximal subungual -white spots (leukonychia) on proximal nail plate, periungual inflammation
5. total dystrophic - thick, opaque, yellow/brown nail
6. candidia - chronic mucocutaeous candidiasis or immunosuppressive with several or all fingers effected by total onychomycosis with
   - periungual inflammation with bulbous or drumstick appearance

Question 36

onychomycosis etiology

Answer 36

1. dermatophytes (fungi need keratin) *most common (trichophyton rubrum/ t.mentagrophytes
2. non dermatophyte molds
3. yeast/candida - rare

Question 37

onychomycosis work up

Answer 37

osi = severity index -score the disease by area involved

1. direct microscopy KOH (rule out fungi)
2. cultures -if pt has been off antifungal for more then 2 weeks
3. PCR (dna)
4. dermoscopy- look for aurora borealis pattern in distal subungual onychomycosis