Introduction to dermatology

Question 1

layers of the skin

Answer 1

epidermis, dermis, and hypodermis (SQ)

Question 2

layers of the epidermis

Answer 2

stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale

Question 3

parts of a complete dermatological exam

Answer 3

good lighting and magnification
assess the skin- haired and non haired
identify lesions- primary vs secondary
which body sites are involved- lesions and distribution
dermogram

Question 4

primary lesions

Answer 4

initial eruption that develops spontaneously as a direct reflection of the underlying disease
appear and disappear quickly

Question 5

secondary lesions

Answer 5

evolve from primary lesions or are artifacts induced by the patients or by external factors such as trauma/biting/licking/medication
usually stay around for a much longer time period

Question 6

types of primary lesions

Answer 6

macule
patch
papule
plaque
vesicle
bulla
wheal
nodule
tumor
cyst

Question 7

types of primary or secondary lesions

Answer 7

alopecia
scale
crust
follicular casts
comedone
pigmentary abnormalities

Question 8

types of secondary lesions

Answer 8

epidermal collarette
scar
excoriation
erosion
ulcer
fissure
lichenification
callus

Question 9

macule

Answer 9

flat spot less than 1 cm on skin with change in skin color

Question 10

patch

Answer 10

macule greater than 1cm

Question 11

purpura, petechia, ecchymoses

Answer 11

type of macule caused by bleeding into the skin

Question 12

papule

Answer 12

small, solid elevation in skin up to 1cm in diameter

Question 13

plaque

Answer 13

coalition of papules forming flat topped elevation

Question 14

pustule

Answer 14

small elevation of epidermis filled with pus

Question 15

vesicle

Answer 15

elevation of epidermis filled with clear fluid

Question 16

bulla

Answer 16

vesicle greater than 1cm in diameter

Question 17

wheal

Answer 17

sharply delineated lesion of edama

Question 18

nodule

Answer 18

solid raised palpable lesion greater than 1cm, can include abscess

Question 19

tumor

Answer 19

large palpable mass- neoplastic enlargement

Question 20

cyst

Answer 20

epithelial lined cavity with solid or fluid material

Question 21

alopecia

Answer 21

absence of hair from area where it is normally present

Question 22

scale

Answer 22

accumulation of loose fragments of horny layer of skin

Question 23

crust

Answer 23

accumulation of dried serum, exudate on surface of skin

Question 24

follicular casts

Answer 24

accumulation of keratin and sebaceous material stuck to a hair shaft

Question 25

comedone

Answer 25

dilated hair follicle filled with debris

Question 26

epidermal collarette

Answer 26

scale arranged in circular pattern. associated with pustule, vesicle, or bullae

Question 27

scar

Answer 27

fibrous tissue has been replaced the damaged dermis or sq tissue

Question 28

excoriation

Answer 28

linear abrasion of the skin

Question 29

erosion

Answer 29

shallow ulcer that does not break basal layer

Question 30

ulcer

Answer 30

break in epidermis with exposure of dermis

Question 31

fissure

Answer 31

linear cleavage in the epidermis or dermis caused by disease or injury

Question 32

lichenification

Answer 32

thickening and hardening of the skin

Question 33

callus

Answer 33

a localized hyperplasia of the stratum corneum of the epidermis caused by pressure or friction. elbows and lateral hock areas are common sites for callus formation in the dog

Question 34

superficial skin scrape

Answer 34

surface mites: sarcoptes, notoedres, otodectes, cheyletiella, demodex gatoi moisten blade with liquid paraffin or KOH or mineral oil scrape a large area because mites are fewer in number if negative, does not rule out superficial mites

Question 35

deep skin scrape

Answer 35

follicular parasites, mostly demodex scrape small focal area with dulled blade using mineral oil induce capillary hemorrhage squeeze follicles if negative, may not rule out follicular parasite scrape multiple affected areas put on glass side, 10x and lower condenser

Question 36

anagen hair

Answer 36

ball or balloon

Question 37

telogen hair

Answer 37

arrow head

Question 38

tape impression smear

Answer 38

place scotch tape onto microscope slide after on skin | 1 drop of #3 diff quick to slide

Question 39

FNA technique

Answer 39

21-23 gauge needle attached to 5ml syringe put needle in lesion; aspirate; pull needle back and redirect into another site; aspirate release pressure on needle before withdrawing disconnect needle from syringe; add few mls of air to syringe and reattach needle express contents in needle on to microscope slide

Question 40

woods lamp

Answer 40

50% of m. canis strains will fluoresce turn on lamp 5-10 minutes prior to use false positives: keratin scale, soaps, dyes, and some medications

Question 41

fungal culture

Answer 41

if hair shafts fluoresce via woods lamp, pluck those for innuculation. if nothing fluoresces, use sterile toothbrush technique DTM- color changes occur, must look at every day dermatophyte used protein in the media resulting in alkaline by products which turn media red at the same time dermatophyte colony appears. must check daily because non pathogenic fungi will use the protein source once carbohydrates are exhausted, but this type of colony would be present for days before the color change

Question 42

skin biopsy indications

Answer 42

nodules/tumors, ulcers/vesicles, severe acute generalized disease, mucosal lesions, footpad lesions, lesions unresponsive to normal therapy

Question 43

skin biopsy protocol

Answer 43

``` no prep, no scrub do not disturb lesion gently clip hair handle sample as little as possible place into formalin and culture pot can use punch, wedge, excisional, or amputation ```

Question 44

bacterial culture and sensitivity

Answer 44

not indicated in all cases of bacterial pyodermas indications: cytology shows cocci and rods or just rods, cocci but no response to correct antibiotic administered correctly, deep pyoderma, chronic AB/GC therapy, GSD pyoderma sample techniques: swab, swab with surface prep, biopsy

Question 45

allergy testing serology

Answer 45

rely on antigen specific antibody levels no vet outlay, quick, no sedation or clipping required no positive control, only detects circulating IgE, lab variations, false positives, grouped allergens, some false negatives NOT reliable for food allergens

Question 46

intradermal allergy testing

Answer 46

gold standard for identifying environmental allergens