Dermatology Introduction

Question 1

Layers of the skin

Answer 1

Stratum basale

Stratum spinosum

Stratum granulosum

Stratum lucidum

Stratum corneum

Question 2

Primary derm lesion

Answer 2

Initial eruption develops spontaneously as a direct reflection of the underlying disease

appears quickly and disappears quickly

Question 3

Secondary dermatology lesions

Answer 3

Evolve from primary lesions or are artefacts induced by external factors (trauma, licking and medication)

Usually stay around for a longer time period

Question 4

Primary lesions

Answer 4

Macules, papules, pustules, vesicles, wheal, nodule, tumor, cyst

Question 5

Primary or secondary skin lesions

Answer 5

Alopecia, scale, crust, follicular casts, comedo, pigmentary abnormalities

Question 6

Secondary skin lesions

Answer 6

Epidermal collarette, scar, excoriation, erosion, fissure, lichenification, callus

Question 7

Macule

Answer 7

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

Question 8

Patch

Answer 8

Macule larger than 1 cm

Question 9

Purpura, petechial, ecchymoses

Answer 9

Type of macule caused by bleeding into the skin

Question 10

Papule

Answer 10

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

Question 11

Plaque

Answer 11

Coalition of papules forming flattopped elevation

Question 12

Pustule

Answer 12

Small elevation of the epidermis filled with pus

Question 13

Vesicle

Answer 13

Elevation of the epidermis filled with clear fluid

Question 14

Bulla

Answer 14

Vesicle larger than 1 cm in diameter

Question 15

Wheal

Answer 15

Sharply delineated lesion of edema

Question 16

Nodule

Answer 16

Solid raised palpable lesion greater than 1 cm

Can include absecess

Question 17

Cyst

Answer 17

Epithelial lined cavity with solid or fluid material

Question 18

Alopecia

Answer 18

Hair loss

Question 19

Scale

Answer 19

Accumulation of loose fragments of horny skin layer

Question 20

Crust

Answer 20

Accumulation of dried serum, exudate on the surface of skin

Question 21

Follicular casts

Answer 21

Accumulation of keratin and sebaceous material stuck to a hair shaft

Question 22

Comedone

Answer 22

Dilated hair follicle filled with debris

Question 23

Epidermal collarette

Answer 23

Scale arranged in circular pattern

Associated with pustule, vesicle or bulla

Question 24

Scar

Answer 24

Fibrous tissue has replaced damaged dermis or s/c tissue

Question 25

Excoriation

Answer 25

Linear abrasion of the skin

Question 26

Erosion

Answer 26

Shallow ulcer that does not break the basal layer

Question 27

Ulcer

Answer 27

Break in epidermis with exposure of dermis

Question 28

Fissure

Answer 28

Linear cleavage (cracks) in the epidermis or dermis caused by disease or injury

Question 29

Lichenification

Answer 29

Thickening and hardening of the skin

Question 30

Callus

Answer 30

Localized hyperplasia of the stratum corenum of the epidermis caused by pressure or friction elbows and lateral hock areas are common sites for callus formation in the dog

Question 31

Superficial skin scrapes are used for

Answer 31

Finding skin mites Sarcoptes, notoedres, otodectes, cheyletiella, demodex gatoi in cats

Question 32

Performing a superficial skin scrape

Answer 32

Moisten blade with liquid paraffin or KOH or mineral oil Scrape a larger area because mites can be few in number

Question 33

If negative for a skin scrape, can you rule out mites?

Answer 33

No

Question 34

Deep skin scrapes look for

Answer 34

Follicular parasites Mostly demodex

Question 35

How to perform a deep skin scrape

Answer 35

Scrape small focal area with a dulled blade using mineral oil Induce capillary hemorrhage Squeeze follicles Put on a glass slide 10 x mucroscope and lower condenser

Question 36

If a deep skin scrape is negative can you rule out follicular parasites

Answer 36

NO

Question 37

Types of hair roots

Answer 37

Anagen hair = ball or balloon Telogen = arrow head

Question 38

What are you looking for in hair plucks

Answer 38

Ringworm Follicle dysplasia Surface parasites

Question 39

What is a trichogram

Answer 39

A hair pluck/ analysis of hair root

Question 40

Acetate tape impression smear

Answer 40

Scotch tape test Place scotch tape onto microslide Add 1 drop of #3 diff quick to slide Looking to see bacteria, fungi and yeast

Question 41

FNA technique

Answer 41

21-23 g needle Attached to 5 ml syringe Put needle in lesion and aspirate from two sites without pulling hte needle out Disconnect needle, add air, reattch needle Put contents on a needle

Question 42

Will woods lamp always show a positive for a M. canis infection

Answer 42

No Only 50% of M. canis strains produce tryptophan metabolites that fluoresce with UV light

Question 43

How long should the Woods lamp be turned on before use

Answer 43

5-10 min

Question 44

Can you have a false positive with a Woods lamp

Answer 44

Yes Can be caused by keratin scale, soap, dye and medications

Question 45

Which animals should recieve a fungal culture

Answer 45

ALL cats with skin disease Dogs with inflammatory lesions

Question 46

If the hair shaft is positive under Wood's lamp, what is the next step

Answer 46

Plug hairs for DTM inoculation

Question 47

If nothing fluoresces with a Woods lamp...

Answer 47

Use the sterile toothbrush technique Comb pet with toothbrush to collect hair/scales used to inoculate media

Question 48

DTM tests must be checked

Answer 48

EVERY DAY Non pathogenic fungi will use the protein sources once carbohydrates are exhausted - causing it to turn red

Question 49

Skin biopsy indications

Answer 49

Nodules/ tumors Ulcers/ vesicles Severe acute generalised disease Mucosal lesions Footpad lesions Lesions unresponsive to normal therapy

Question 50

Skin biopsy steps

Answer 50

No prep or scrub Do not disturb lesions Gently clip hair Handle the sample as little as possible Place into formalin and culture

Question 51

Types of skin biopsy techniques

Answer 51

Punch biopsy Wedge/ excisional biopsy Amputation- nail or toe

Question 52

Indications for bacterial culture and sensitivity

Answer 52

Cytology shows cocci and rods or just rods Cocci but no response to the right antibiotics given at the right time Deep pyoderma Chrinic antibody and glucocorticoid therapy GSD pyoderma

Question 53

Gold standard test for environmental allergens

Answer 53

Intradermal allergy testing

Question 54

Allergy testing with Serology advantages

Answer 54

No vet outlay Quick No sedation or clipping required

Question 55

Disadvantages of allergy testing

Answer 55

No positive control Only detects circulating IgE Lab variations False positives Grouped allergens/ limited Can have false negatives Not reliable for food allergens