Erosions/ulcers 1

Question 1

erosions

Answer 1

Partial loss of epidermis
Does not penetrate the basement membrane
Heals without scarring

Question 2

Ulcers

Answer 2

Full loss of epidermis
Penetrate & extend beyond basement membrane
Heals with scarring

Question 3

Trauma classification of lesion

Answer 3

Pyotraumatic dermatitis*
Intertrigo (skin fold pyoderma)

Question 4

Ischemia classification of lesion

Answer 4

Vasculitis*

Question 5

Metabolic classification of lesion

Answer 5

Necrolytic migratory erythema

Question 6

Neoplasia classification of lesion

Answer 6

Squamous cell carcinoma*
Cutaneous lymphoma*

Question 7

Pyotraumatic dermatitis

Answer 7

Very common in dogs - thick coated breeds
“Hot spot” or acute moist dermatitis - condition can develop quickly

Question 8

Clinical features of PTD

Answer 8

Acute onset**
Usually localized
Self inflicted trauma due to an underlying pruritic skin condition

Question 9

Underlying causes of PTD

Answer 9

Allergic skin disease
Otitis externa
Ectoparasites
Matted hair
Itching can cause excessive biting, licking, scratching
Secondary bacterial infection is often a sequelae (super/deep)

Question 10

Treating PTD

Answer 10

Clip affected areas
Clean w non irritating antibacterial solution - chlorhexidine
Topical/systemic glucocorticoids 5-14d depending on severity
Topical antiseptic or antibiotic for superficial lesion
Systemic antibiotic for deep lesion
PREVENT further trauma

Question 11

Intertrigo
Skin fold pyoderma

Answer 11

Common in dogs
Name is based off location of lesion

Question 12

names of Intertrigo & breeds

Answer 12

Lip fold pyoderma - spaniel breeds
Facial fold pyoderma - Brachycephalic breeds
Tail fold pyoderma - screw tails breeds
Volume fold pyoderma - obese animals

Question 13

Pathogenesis of Intertrigo

Answer 13

1. Two skin surfaces being rubbed together leading to trauma
2. Poor ventilation
3. Accumulation of moisture (tears, saliva, urine, sebum)
4. Over colonization of microorganism such as yeast & bacterial exacerbate the inflammation

Question 14

Treating skin fold pyoderma

Answer 14

Condition is an anatomical problems = no fix w med TX
Tx is often long term, surgery can be considered
1. Clean non-irritant antibacterial solution - chlorhexidine
2. Topical antiseptic/biotic therapy based on cytology
3. Weight loss for obese animals

Question 15

Erosion/ulcers of ischemia

Answer 15

Inflammation of blood vessels which can lead to
1. Leaky BV wall & OR
2. Occlusion of BV lumen (thrombosis)

Question 16

Distribution of vasculitis

Answer 16

Common in extremities initially but can be generalized
1. Paws/pads
2. Tail
3. Ear tips/margin
4. Nose

Question 17

Skin lesion of vasculitis progression

Answer 17

Superficial - slow progression to alopecia
Deep & rapid progression to alopecia, erosion, ulceration, crusting and scars

Question 18

Pathogen of vasculitis

Answer 18

Leak blood vessel wall —> extravasation of RBC into dermis —> petechia (pin point) hemorrhage
Early lesion, skin can appear red
Older lesions, skin turns purplish

Question 19

Determining red discoloration of skin rash vs erythema (congestion) vs vasculitis (petechial hemorrhage)

Answer 19

Diascopy - pressing skin
Vasodilation - erythema, skin would blanche
Vasculitis - pressure will not cause coloration to disappear

Question 20

Vasculitis is not…

Answer 20

A disease !!
Look for underlying disease factors
Infectious: RMSF, ehrlichiosis, bacterial sepsis
ADR: drugs/vax
Autoimmune: systemic lupus, cold agglutinin disease

Question 21

DX for vasculitis

Answer 21

Skin biopsies from affected areas
Avoid collecting from ulcerated skin
Take multiple biopsies bc the changes in skin can be subtle
Inform pathologist that you are suspicious of possible vasculitis/vasculopathy

Question 22

TX of vasculitis

Answer 22

1. Treat underlying cause
2. Drugs can be used to treat immune mediated vasculitis
   - Pentoxifylline
   - glucocorticoids
   - cyclosporine

Question 23

Metabolic erosions/ulcers

Answer 23

Necrolytic migratory erythema ALSO
Hepatocuatnous syndrome*
Superficial Necrolytic dermatitis
Metabolic epidermal necrosis

Question 24

NME pathogenesis

Answer 24

Common in older dogs
Underlying conditions
- chronic hepatic disease (80%)
- phenobarbital associated hepatitis
- pancreatic glucagonma
- atrophic enteritis
Poorly understood - associated w low serum amino acids

Question 25

Non-derm signs of NME

Answer 25

Lethargy /weakness Lameness (due to lesions in foot pads) Inappetance PU/PD - where there is concurrent diabetes mellitus or hepatic dysfunction

Question 26

Skin lesions of NME

Answer 26

1. Footpads** 2. Mucocutaneous junctions 3. Pressure points on limbs 4. Areas of friction 2-4 = erosions & crusts

Question 27

Appearance of footpads

Answer 27

Hyperkertotic, crusting, fissuring, ulcerations. Interdigital secondary infections w Malassezia or candida is common

Question 28

DX of NME

Answer 28

Skin biopsy of inflamed lesions NEVER biopsy entirely eroded or ulcerated lesion Abdominal ultrasound : honeycomb/Swiss cheese pattern of liver MAY be seen

Question 29

TX of NME

Answer 29

Therapy is usually supportive/palliative & depends on underlying cause Prognosis is poor (6-12m survival)

Question 30

Effective TX of NME

Answer 30

Intravenous amino acids** High quality protein diet Zinc supplementation Essential fatty acids Treat secondary infections

Question 31

Mechanism of erosion/ulcer in types of neoplasia

Answer 31

Tumors require nutrients to grow = secrete angiogenic factors which form a unique blood supply to the tumor This can lead to tumor hypoxia = rapid growth demands more blood which can’t keep up = ischemic necrosis = erosion /ulceration

Question 32

Cytotoxicity

Answer 32

Cells getting toxic = death Can cause epidermis to necrotize

Question 33

SCC erosions and ulceration

Answer 33

Most common epithelial cancer of dogs and cats In cats - caused by chronic exposure to UV light White cat = more prone to develop Can occur from certain strains of papilloma virus

Question 34

Progression of SCC

Answer 34

Localized proliferative tumors that tend to ulcerate = tissue destruction Rarely metastasizes or spreads hemo or lymph

Question 35

DX of SCC

Answer 35

Skin biopsy

Question 36

Tx of SCC

Answer 36

Surgical excision - most successful Radiation therapy - best when combined w surgery Cryosurgery /electrosurgery Intralesional chemo Tropical imiquimod

Question 37

Cutaneous lymphoma

Answer 37

Rare in cats/dogs Dogs - presentation is highly variable and mimics other dermatoses Also called cutaneous epitheliotrophic T cell lymphoma, cutaneous lymphosarcoma

Question 38

Skin lesion of cutaneous lymphoma

Answer 38

Erythema Plaques Erosion/ulcer Mucosal lesion

Question 39

DX of cutaneous lymphoma

Answer 39

SKIN BIOPSY Which lesions?? - depigmented lesions - lesions w loss of architecture - erythematous and scaly lesions - plaques or nodules NEVER biopsy entirely ulcerated lesions

Question 40

TX of cutaneous lymphoma

Answer 40

GRAVE prognosis 6-9m Treatment is only palliative REFER for recommended treatment