Superficial, cutaneous, subcutaneous, fungal infections Flashcards Preview

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Flashcards in Superficial, cutaneous, subcutaneous, fungal infections Deck (39):
1

what layer of the skin does superficial fungi infect

stratum corneum

2

pityriasis versicolor (tinea versicolor)
caused by
what promotes its growth

- common superficial infection of the skin caused by malassezia furfur
-dimorphic
-malassezia is part of our normal flora- found in lipophilic places- head, neck etc
-disease shows when environment promotes hyphal phase- like increased lipid production and moist heat

3

symptoms of pityriasis versicolor

-failure to tan- hypopigmentation (I pity you for your lack of a tan)- what levi had
- irregular scaly patches and yellow brown to dark brown color
-hyper/hypopigmentation
-primarily cosmetic

4

pityriasis versicolor diagnosis

- direct observation of skin scrapings and prepare WITH KOH PREP TO REVEAL "SPAGHETTI AND MEATBALLS"- yeast and hyphae
-don't need to culture- grows slow and requires olive oil

5

treatment of pityriasis versicolor

- topical-head to toe with KERATOLYTIC AGENTS LIKE SELENIUM SULFIDE AND SALICYLIC ACID) to remove organisms from the skin
-azoles
-relapse is common
-must change hygiene issues or physiology

6

Tinea nigra

- brown/black oval-shaped lesions of the skin
-caused by inoculation of superficial skin via contamination by soil, sewage wood or compost
-caused by EXOPHIALA WERNECKII
- most common in warm places- Texas, Carolinas, Alabama, Louisiana, FL

7

why does exophiala werneckii cause brown/black pigment

- produces melanin

8

diagnosis of tinia nigra

- skin scrapings (KOH) reveal TWO CELLED YEAST FORMS WITH DARK PIGMENT

9

Tinea nigra treatment

wash off with salicylic acid and selenium sulfide
azoles

10

black and white peidra
what are they
where can they be found?
what organisms cause black? white?

-hard gritty "stone" like granules on hair shaft
-can be found in soil or compost
- black = peidra hortae
white = trichosporon beigelii ( like white= beige)

11

from what can white piedra be contracted

contact with animals

12

how do you tell the difference between white and black peidra?

- white is fluffy collar around hair shaft, loosely adherent to pubic, axillary hair, beards and eyebrows
-black peidra- nodules that are hard- usually on scalp and firmly attached

13

diagnosis and treatment of black and white peidra

- microscopic examination of infected hairs
-treatment- shaving off the hair and practicing good hygiene

14

dermatophytes

- group of organisms causing infection so the skin, nails, and hair- generally limited to keratinized layers, epidermis and dermis

15

what are the three most common dermatophytes
-what are they capable of that helps them grow

- microsporum
-trichophyton
-epidermophyton
-> capable of degrading and using keratin as a nutrient source

16

what do dermatophytes typically induce?
infection symptoms
infections are referred to as....

- inflammatory reaction around the underlying tissue and can appear as circular (like ringworm)
-infections- itching, scaling of skin
-referred to as tinea and the anatomic position

17

tinea pedis

- chronic often
-look like dry skin and have pustules at the periphery of disease where active growth is occurring
- in toe webs and maybe heel and sides of foot/nails

18

tinia corporus

- dry lesions-red, round scaly with raised boarder
-inflamed periphery and pustules
-anywhere but typically on trunk

19

tinea captitis

- scalp infection
- distinct scaly lesion- patches of hair loss
-fungal elements can surround the hair or be present within the hair shaft
-FLAVUS- MASS OF HYPHAL ELEMENTS SURROUNDING THE BASE OF THE HAIR SHAFT

20

tinea cruris

-jock itch
-"crura"
- lesions present in the groin
-90% in men
-rounded boarder with raised boarders

21

tinea unguium-onychomycosis

- infection of the nail plate and bed
- hyperkeratosis and discoloration- dry, cracked and brittle disfigured nail
-painful
-DM and AIDS pt

22

diagnosis of tinea unguium

- see fungal elements via hair and nail samples
- confirms fungal involvement but DOES NOT REVEAL IDENTITY- NEED MICRO/MACRO AND METABOLIC CHARACTERISTICS
- WOODS LAMPS- UV LAMP THAT FLUORESCE SOME BUT NOT ALL FUNGI BUT HELPS WITH CHOOSING WHAT HAIR TO PLUCK

23

why is it difficult to treat tinea unguium?

- because it's hard for topical treatments to penetrate nail bed
-must take oral meds

24

treatment for dermatophyte infections

- treat with exfoliate agent and topical azoles
-GRISEOFULVIN (greasy like your head) frequently used to treat tinea capitus
-

25

candidiasis

-caused by many yeasts but most common is c. albicans
- causes diaper rash and dishawasher's hands
-look like papulues or plaques-redness, tenderness and cracking
-usually between webbings
-flakey. scaly

26

forms of c. albicans

yeast- normal flora
hyphal forms- tissue
pseudohyphal

27

chronic mucocutaneous candidiasis

- superficial infections at several anatomical sites like the mouth, face and nails
-associated with t cell deficits and endocrine disorders
-granulomatous response to infection causes disfigurement and discomfort
-IMMUNOSUPPRESSED PEOPLE

28

Disseminated candidiasis

- increase colonization by disrupting normal flora
- breakdown of normal physical barriers
-immune suppression
-it is the hematogenous spread of organisms to the liver, spleen, lungs and eyes, bones and joints

29

treatment for candidiasis?

-IV amphotericin B with or without fluconazole

30

sporotrichosis

- infection of cutaneous and subcutaneous tissue with lymphatics
- caused by sporothrix schenckii - dimorphic fungus found in soil/nature
-traumatic inoculation- moss, rose spliters, wood splinter

31

presentation of sporotrichosis

- inflammation at site of inoculation followed by painless granuloma
-ulcerates and creates open sore- as this happens, organism is spreading along lymphatics

32

diagnosis ad treatmet of sporotrichosis

- not really observed in tissue
- must cultivate from pus or tissue

treat- oral potassium iodide, oral azoles

33

chromoblastomycosis

-seen in tropics
- traumatic inoculation of soil fungi
-presents as a wartlike lesion and then develops into red/gray (IE CHROMO) CAULIFLOWER like lesions THAT ARE
-painless

34

Diagnosis and treatment of chromoblastomycosis

- brown-pigmented hyphae in skin scrapings
- MEDLAR BODIES - COPPER COLORED SPHERICAL CELLS

35

treatment of chromomycosis

- surgical removal of lesions
- oral antifungals- 5fluorocytosine

36

mycetoma

- Madura foot
-chronic, subcutaneous infection usually of foot
-obtained thru traumatic inoculation of soil-inhabiting fungi

37

mycetoma progression of disease

- usually slow
-starts with papule at site of inoculation
- lesion ulcerates releasing pus and blood
-draining tracts or sinuses develop causing discharge
-underlying bone involved makin gpitting lesions

38

diagnosis of mycetoma

- observation of colored GRAINS IN PUS, TISSUE AND DISCHARGE- compacted hyphae

39

treatment of mycetoma

surgery and antifungal