Lecture 26: Integument 2

Question 1

Provide 6 examples of portals of entry into the adnexa/epidermis and SC

Answer 1

direct trauma

ganglion migration

absorption

UVA

drug

toxins

Question 2

List the 6 different inflammatory patterns of the dermis and subcutis

Answer 2

Perivascular/interstitial dermatitis

vascultitis

interface dermatitis

nodular and diffuse

subepidermal vesicular and pustular dermatitis

atrophic dermatosis

Question 3

What is the most common inflammatory pattern affecting the dermis and subcutis

Answer 3

perivascular/interstitial dermatitis

Question 4

Define perivascular/interstitial dermatitis

Answer 4

leukocytes move out of vessel and into the perivascular dermis

non specific

Question 5

What are 3 types of perivascular/interstitial dermatitis

Answer 5

perivascular/interstitial dermatitis

spongiotic perivascular/interstitial dermatitis

hyperplastic perivascular/interstitial dermatitis

Question 6

What is the common cause of perivascular/interstitial dermatitis? What are the common lesions?

Answer 6

hypersensitivity

urticaria (hives)

Question 7

What are 5 common causes of spongiotic perivascular/interstitial dermatitis?

Answer 7

immune mediated

hypersensitivity

contact dermatitis

virus

dermatophytosis
- malassezia/yeast

Question 8

What are 4 common causes of hyperplastic perivascular/interstitial dermatitis

Answer 8

chronic dermatitis

hypersensitivity

lick dermatitis

keratinization

Question 9

What animals are most commonly affected by perivascular/interstitial dermatitis

Answer 9

horses and cats

Question 10

List 3 common causes of eosinophilic inflammation

Answer 10

perivascular/interstitial dermatitis
- ectoparasite/allergy/HS

Zn dermatosis
- hyperkeratosis

chronic pyoderma
- staph infection

Question 11

What are the clinical signs of perivascular/interstitial dermatitis

Answer 11

pruritis

initially no lesions - will develop over time

Question 12

What is vasculitis? What are 6 common causes

Answer 12

leukocytes targeting vessel walls leading to inflammation, necrosis, and thrombosis

infecting
immune injury
toxin
photodamage
DIC
immune mediated due to type 3 HS (antigen-Ig complex)

Question 13

List 4 common types of vasculitis

Answer 13

septic

neutrophilic

lymphocytic

eosinophilic

Question 14

What characterizes septic vasculitis

Answer 14

bacterial antigens in the vessel wall

Question 15

What are the features of neutrophilic vasculitis

Answer 15

most common vasculitis

leukocytoclastic (neutrophils explode and leave nuclear dust)
non-leukocytoclastic

Question 16

A pig is presented to you with geometric patterns of macules and ischemic necrosis. What is you top differential? What is a primary cause of the lesions?

Answer 16

septicemia due to erysipelothrix rhusiopathiae

lesions caused by neutrophilic vasculitis leading to inflammation, necrosis, and thrombosis

Question 17

What are 2 main causes of neutrophilic vasculitis

Answer 17

hypersensitivity
- equine purpura hemorrhagicae

septicemia

Question 18

What is a common cause of lymphocytic vasculitis and what are the clinical signs

Answer 18

vaccine induced panniculitis

clinically they will have thin, alopecic hair follicles

Question 19

What are some causes of eosinophilic vasculitis

Answer 19

arthropod/drug/HS/feline eosinophilic granuloma

overall rare

Question 20

What are 2 types of interface dermatitis and how do they differ? Provide examples of causes of each

Answer 20

cell poor: mild lymphocyte inflam
- dermatomyositis

cell rich: lots of inflammation and apoptosis of basal epithelium
- lupus erythematous
- mucocutaneous pyoderma

Question 21

What are the common clinical signs of interface dermatitis

Answer 21

pigment incontinance and alopecia

usually affecting the epidermal-dermal border and the basal epithelial keratinocytes

Question 22

List 4 types of nodular and diffuse inflammation in the dermis and SC. List their respective causes

Answer 22

granulomatous
- trauma/FB implant

neutrophilic/abcess
- bacteria/fungi/algae/protozoa/sterile FB

histiocyte (chronic granuloma)
- sporothrix (fungi)
- staph/strep/peudomonas aeruginosa
- actinobacillus ligneresii
- proteus
-nocaria
-actinomyces
-streptomyces

eosinophil
- habronema
- stephanofilaria

Question 23

What are the lesions associated with subepidermal vesicular and pustular dermatitis

Answer 23

fragile and transient vesicles

Question 24

What are the 2 types of subepidermal vesicular and pustular dermatitis

Answer 24

intraepidermal vesicles and pustules

subepidermal vesicles

Question 25

What is intraepidermal vesicles and pustules characterized by histologically? What causes it?

Answer 25

acantholysis and neutrophils with intracellular edema +/-intercellular edema bacterial infections pemphigus autoantibodies viral

Question 26

What causes subepidermal vesicles? What are the common clinical signs

Answer 26

defective or autoimmune reactions against adhesion molecules causing subepidermal edema and urticaria/cellulitis

Question 27

What is atrophic dermatosis? What are the clinical signs? What causes it?

Answer 27

atrophic follicles with epidermal, sebaceous, and dermal atrophy +/- hyperkeratosis and follicular keratosis thin skin and small adnexa characteristic of endocrine disorders like cushings

Question 28

What is the main lesions in acute dermatitis

Answer 28

wheal formation due to acute inflammation dermal edema due to perivascular edema and lymphatic dilation

Question 29

What is deep pyoderma? What animals is it most common in?

Answer 29

bacterial infection of hair follicles and dermis +/- SC not super common - higher risk if low immunity/demodex/follicular hyperkeratosis mainly in dogs

Question 30

What is a common causative agent of deep pyoderma

Answer 30

Staphylococcus pseudointermedius - gram (+) - folluculitis and furunculosis in dogs secondary infections from gram (-) - Pseudomonas - proteus - e. coli

Question 31

List 7 types of inflammation affecting the adnexal structures in the skin

Answer 31

perifolliculitis mural folliculitis: inflam in wall of follicle luminal folliculitis: inflam in lumen of follicle furunculosis: rupture out of follicle bulbitis: hair bulb sebaceous adenitis

Question 32

What is perifolliculitis? What is a common cause?

Answer 32

inflammation around the follicle demodex in dogs

Question 33

What is bulbitis

Answer 33

immune mediated inflammation in the hair bulb usually associated with T cells

Question 34

What is the primary clinical sign of bulbitis

Answer 34

alopecia hair bulb atropy causes transition to the telogen (inactive) phase of the hair)

Question 35

What is sebaceous adenitis? What is the main clinical sign

Answer 35

cell mediated inflammation of the sebacous gland it is idiopathic causes alopecia

Question 36

Describe the steps of folliculitis progression

Answer 36

perifollicular migration mural folliculitis luminal folliculitis furunculosis inflammation extends deeper forming an abscess or sinus

Question 37

What is panniculitis and what are 5 causes

Answer 37

inflammation of the SC infection immune mediated physical trauma nutritional disorder pancreatic disease

Question 38

What are the gross lesions of pannicultis? List 4 types of panniculitis

Answer 38

nodules that ulcerate and drain oily/hemorrhagic fluid neutrophilic lymphocytic granulomatous-pyogranulomatous with pathogen granulomatous-pyogranulomatous without pathogen

Question 39

What are the common causes of primary and secondary panniculitis respectively

Answer 39

1 - SC adipose - feline pansteatitis: occur if fed a diet high in polyunsaturated fatty acids and low in antioxidants = lipid peroxidation and pyogranuloma formation 2: contiguous dermal inflammation that connects with the deep SC

Question 40

What is cellultitis? What are the clinical signs

Answer 40

very deep purulent to pyogranulomatous inflammation +/- hemorrhage, necrosis, thrombosis +/- bacteria causing tissue devitalization and sloughing swelling/erythema/fever/lymphomegaly

Question 41

What is a severe form of cellulitis? What is it caused by?

Answer 41

necrotizing fasciitis Streptococcus canis or Staphylococcus pseudointermedius

Question 42

What are 4 outcomes of dermal/SC inflammation/injury

Answer 42

resolution abcess heal with scar chronic - delayed HS/granuloma/FB/autoimmune

Question 43

What is fibrosis/fibroplasia/sclerosis? What is its significance

Answer 43

reduced adnexa and restriction of movement ex. horse + proud flesh

Question 44

What are 2 things that can cause solar elastosis

Answer 44

sun exposure neoplasia (SCC) chronic injury (fibroblast injury) overall rare

Question 45

What are 5 types of follicular changes

Answer 45

atrophy dilation inflammation keratosis dysplasia

Question 46

What are 4 types of gland changes

Answer 46

inflammation atrophy hyperplasia cysts

Question 47

What is a normal example of follicular dysplasia?

Answer 47

coat colour dilution

Question 48

What is an example of collagen dysplasia?

Answer 48

ehlers danlos reduced tensile strength and increased stretch histologically normal higher risk of secondary infection

Question 49

What is 'flame figure' collagen degeneration? What is it usually associated with

Answer 49

dermal deposit of eosinophilic material on collagen it is common with eosinophilic disorders - eosinophilic dermatitis

Question 50

What is eosinophilic dermatitis? What are common causes

Answer 50

cutaneous reactions that can include feline eosinophilic granuloma complex or plaque/rodent ulcers canine eosinophilic granuloma equine nodular collagenolytic granuloma

Question 51

What animals are primarily affected by eosinophilic dermatitis

Answer 51

cats and horses

Question 52

Give one example of collagen mineralization

Answer 52

calcinosis cutis due to excess glucocorticoids (iatrogenic or cushings)

Question 53

What is calcinosis circumscripta? What species is mainly affected

Answer 53

foci of mineralization in areas of trauma that +/- are associated with metastatic calcification of renal failure mainly dogs

Question 54

List 3 types of abnormal dermal deposits

Answer 54

calcinosis circumscripta amyloid mucin

Question 55

What causes mucin accumulation in the dermis? What is it?

Answer 55

glucosaminoglycan (GAG) - protein + hyluronic acid which binds water. myxedema of hypothyroidism mucinosis share pei