Dermatitis 2

Question 1

What is puppy strangles? What is the gross appearance?

Answer 1

Juvenile sterile granulomatous dermatitis

Pustules, nodules, swelling of face, ears, mucocutaneous junctions

Question 2

You have a puppy that presents with fever and joint pain. Grossly you see pustules, nodules, swelling of face and ears, and mucocutaneous junction.

You take a biopsy that shows..
granulomaouts dermatitis and panniculitis

What is it?

Answer 2

Puppy strangles

Juvenile sterile granulomatous dermatitis

Question 3

What are infectious causes of granulomas?

Answer 3

Fungal - pythium and langenidium spp

Bacterial - Nocardia, Actinomyces, mycobacterium

Question 4

On a dog you see…
nodules, ulceration, draining sinuses with involvement of underlying bone. You also see what appear to be sulfur granules.

What is your DDX?

Answer 4

Actinomyces mycetoma (filamentous bacteria)

Nocardia-> should be ruled out because of involvement of underlying bone

Pyogranulomatous dermatitis

Question 5

What causes feline leprosy?

Answer 5

Mycobacterium lepraemurium -> obligate intracellular , gram positive bacteria

–> granulomatous dermatitis

Question 6

What cats are predisposed to feline leprosy?

Answer 6

Cat in cold, wet areas

FIV/debilitation

Question 7

T/F: feline leprosy can be diagnosed by culturing the bacteria

Answer 7

F

DOES NOT grow in culture
Must use PCR

Question 8

What is the cause of opportunist mycobacteriosoiss?

Answer 8

Facultative saprophytes

Infection tends to occur in wound contamination or traumatic implantation

Question 9

In a Boxer you see..

Nodules involving the dorsal pinna.
What is the most likely cause?

Answer 9

Canine leproid granuloma

Saprophytic mycobacterium

Question 10

How can you diagnose canine leproid grauloma ?

Answer 10

Difficult to culture
PCR

Can usually be found on histo-> acid fast

Question 11

What is a lick granuloma?

Answer 11

Common in dog
- not really a granuloma!

Epidermal hyperplasia, granulation tissue, fibrosis
Caused by persistent licking/chewing

Question 12

What are the gross lesions of a eosinophilic dermatitis?

Answer 12

Erythema
Alopecia
Scaling

Question 13

Your histology report comes back with…
Eosinophilic dermatitis with epidermal hyperplasia.

What do you suspect the cause is??

Answer 13

Allergic skin disease

Question 14

What are the 4 types of allergic skin disease

Answer 14

Atopic
Food allergy
Contact hypersensitivity
Insect bite hypersensitivity

Question 15

Grossly you have a dog with..
erythema, alopecia, and excoriation
Papules, pustules, and crusts,
Lichenifiication, hyperpigmentation

Histology shows..
lymphocytic and eosinophilic dermatitis

Answer 15

Allergic skin disease

Question 16

In allergic skin disease, erythema, alopecia, and excoriation is due to __________________, papules, pustules, and crusts are due to ________________, and lichenifiication and hyperpigmentation is due to _____________.

Answer 16

Self- trauma

Secondary pyoderma

Chonicity

Question 17

What is the pathogenesis of atopy?

Answer 17

Type 1 hypersensitivity to environmental allergens

Question 18

What is the distribution of atopy??

Answer 18

Ventrum
Face
Distal extremities

Question 19

What is the pathogenesis of contact dermatitis ?

Answer 19

Type 4 hypersensitivity -> exposure via direct contact

Question 20

What type of molecules cause contact dermatitis? And how do they cause the inflammatory reaction

Answer 20

Low molecular weight haptens present in chemicals require binding to cell-associated proteins prior to being recognized by CD8+ Tcells

Question 21

What is the distribution of contact dermatitis?

Answer 21

Depends on site of contact, often poorly haired areas

Question 22

What is the pathogenesis of insect bite hypersensitivity ?

Answer 22

Type 1 and 4 hypersensitivity

Question 23

What is the distribution of insect bite hypersensitivites ?

Answer 23

Depends on area of bite, but can become generalized

Question 24

What military dermatitis?

Answer 24

Pattern of lesions (NOT a disease)

Small erytematous papules - commonly seen in cats with allergic skin disease

Question 25

What is eosinophilic granuloma complex?

Answer 25

Pattern of lesions (Not a disease ) Indolent ulcer Eosinophilic plaque Eosinophilic granuloma

Question 26

What are causes of eosinophilic granulomas?

Answer 26

Parasite reaction Insect bite hypersensitivity Forgiven body reaction

Question 27

What is an indolent ulcer?

Answer 27

Ulcer on upper lip

Question 28

What is an eosinophilic plaque?

Answer 28

Discrete red to ulcerated plaque on abdomen or medial thigh

Question 29

What is an eosinophilic granuloma?

Answer 29

Nodules on thigh, face, or mouth

Question 30

Horse Multiple coalescing nodular granulomas and ulcerated areas in medial canthus of the eye What is the MDx and the most likely cause?

Answer 30

Eosinophilic and granulomatous dermatitis Habronemiasis (summer sores) -> larval migration of Habronema or Draschia sp. ->> deposited by house or stable flies

Question 31

On a doggo you see... Depigmentation, erythema, scaling, erosion, ulceration, and crusting at the junction of the nose-> muzzle What is your DDX?

Answer 31

Uveodermatologic syndrome - auto-immune disease against dermal and uveal melanocytes Dermtomyositis

Question 32

What is the distribution of discoid lupus erthematosus?

Answer 32

Dorsal nose and nasal plenum >>> pinnae, lips, periocular >>> oral mucosa

Question 33

How should you differentiate circulatory disorders of the skin?

Answer 33

Discrete reddened area -> hemorrhage Linear pattern Geometrical shapes Vascular lesions resulting in ischemia -> degeneration/necrosis

Question 34

What are the 4 main mechanisms of subcutaneous edema?

Answer 34

Increased hydrostatic pressure (eg. congestive heart failure) Decrease oncotic pressure Increased vascular permeability Lymphatic obstruction

Question 35

How can you differentiate between congestion and hemorrhage?

Answer 35

Push on area: Blanching => congestion Remains reddened => hemorrhage

Question 36

What is the cause of multifocal cutaneous ecchymosis hemorrhages?

Answer 36

Primary hemostasis defect Vasculitis vs thrombocytopenia

Question 37

Pig Sharply demarcated geometrical shaped dark red to blue area Some are firm, dry, sucked, darkened What is your DDX?

Answer 37

Vasculitis (bacteria, snake bite, drug reaction, secodary to ulceration Frostbite Toxins causing extreme vasoconstriction

Question 38

What is diamond skin disease caused by?

Answer 38

Erysipelothrix rhusiopathiae

Question 39

What causes the lesions of Diamond skin disease?

Answer 39

Vasculitis/ thrombosis -> infarction -> necrosis of the dermis and epidermis

Question 40

What is the pathogenesis of purpura hemorrhagica?

Answer 40

Type 3 hypersensitivity immune mediated vasculitis

Question 41

In a horse you see.. Red or purple macules/patches in the skin or mucous membranes

Answer 41

Purpura hemorrhagica -> ecchymotic hemorrhage Strep equi infection

Question 42

What is the pathogenesis of frost bite?

Answer 42

Formation of ice crystals which disrupt cells -> vasoconstriction and endothelial damage -> reduced blood flow-> thrombosis -> infarction

Question 43

What is the distribution of frost bite?

Answer 43

Extremities

Question 44

What is a wheal?

Answer 44

Irregular-shaped area of cutaneous edema; transient, solid elevations

Question 45

What is the pathological process of a wheal?

Answer 45

Vascular disorder

Question 46

Who gets urticaria (Hive)

Answer 46

Dogs and horses

Question 47

What is urticaria?

Answer 47

Localized area of edema involving superficial dermis

Question 48

What is angioedema?

Answer 48

Localized area of edema involving dermis and subcutis

Question 49

What is the pathogenesis of urticaria?

Answer 49

Type 1 and 3 hypersensitivity; mast cells degraulation -> focal edema, congestion, and pruritus

Question 50

What are triggers for urticaria?

Answer 50

Food, drug, antisera, and insect stings