Erosions/ulcers 1 Flashcards
erosions
Partial loss of epidermis
Does not penetrate the basement membrane
Heals without scarring
Ulcers
Full loss of epidermis
Penetrate & extend beyond basement membrane
Heals with scarring
Trauma classification of lesion
Pyotraumatic dermatitis*
Intertrigo (skin fold pyoderma)
Ischemia classification of lesion
Vasculitis*
Metabolic classification of lesion
Necrolytic migratory erythema
Neoplasia classification of lesion
Squamous cell carcinoma*
Cutaneous lymphoma*
Pyotraumatic dermatitis
Very common in dogs - thick coated breeds
“Hot spot” or acute moist dermatitis - condition can develop quickly
Clinical features of PTD
Acute onset**
Usually localized
Self inflicted trauma due to an underlying pruritic skin condition
Underlying causes of PTD
Allergic skin disease
Otitis externa
Ectoparasites
Matted hair
Itching can cause excessive biting, licking, scratching
Secondary bacterial infection is often a sequelae (super/deep)
Treating PTD
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
Intertrigo
Skin fold pyoderma
Common in dogs
Name is based off location of lesion
names of Intertrigo & breeds
Lip fold pyoderma - spaniel breeds
Facial fold pyoderma - Brachycephalic breeds
Tail fold pyoderma - screw tails breeds
Volume fold pyoderma - obese animals
Pathogenesis of Intertrigo
- Two skin surfaces being rubbed together leading to trauma
- Poor ventilation
- Accumulation of moisture (tears, saliva, urine, sebum)
- Over colonization of microorganism such as yeast & bacterial exacerbate the inflammation
Treating skin fold pyoderma
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
Erosion/ulcers of ischemia
Inflammation of blood vessels which can lead to
1. Leaky BV wall & OR
2. Occlusion of BV lumen (thrombosis)
Distribution of vasculitis
Common in extremities initially but can be generalized
1. Paws/pads
2. Tail
3. Ear tips/margin
4. Nose
Skin lesion of vasculitis progression
Superficial - slow progression to alopecia
Deep & rapid progression to alopecia, erosion, ulceration, crusting and scars
Pathogen of vasculitis
Leak blood vessel wall —> extravasation of RBC into dermis —> petechia (pin point) hemorrhage
Early lesion, skin can appear red
Older lesions, skin turns purplish
Determining red discoloration of skin rash vs erythema (congestion) vs vasculitis (petechial hemorrhage)
Diascopy - pressing skin
Vasodilation - erythema, skin would blanche
Vasculitis - pressure will not cause coloration to disappear
Vasculitis is not…
A disease !!
Look for underlying disease factors
Infectious: RMSF, ehrlichiosis, bacterial sepsis
ADR: drugs/vax
Autoimmune: systemic lupus, cold agglutinin disease
DX for vasculitis
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
TX of vasculitis
- Treat underlying cause
- Drugs can be used to treat immune mediated vasculitis
- Pentoxifylline
- glucocorticoids
- cyclosporine
Metabolic erosions/ulcers
Necrolytic migratory erythema ALSO
Hepatocuatnous syndrome*
Superficial Necrolytic dermatitis
Metabolic epidermal necrosis
NME pathogenesis
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
Non-derm signs of NME
Lethargy /weakness
Lameness (due to lesions in foot pads)
Inappetance
PU/PD - where there is concurrent diabetes mellitus or hepatic dysfunction
Skin lesions of NME
- Footpads**
- Mucocutaneous junctions
- Pressure points on limbs
- Areas of friction
2-4 = erosions & crusts
Appearance of footpads
Hyperkertotic, crusting, fissuring, ulcerations. Interdigital secondary infections w Malassezia or candida is common
DX of NME
Skin biopsy of inflamed lesions
NEVER biopsy entirely eroded or ulcerated lesion
Abdominal ultrasound : honeycomb/Swiss cheese pattern of liver MAY be seen
TX of NME
Therapy is usually supportive/palliative & depends on underlying cause
Prognosis is poor (6-12m survival)
Effective TX of NME
Intravenous amino acids**
High quality protein diet
Zinc supplementation
Essential fatty acids
Treat secondary infections
Mechanism of erosion/ulcer in types of neoplasia
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
Cytotoxicity
Cells getting toxic = death
Can cause epidermis to necrotize
SCC erosions and ulceration
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
Progression of SCC
Localized proliferative tumors that tend to ulcerate = tissue destruction
Rarely metastasizes or spreads hemo or lymph
DX of SCC
Skin biopsy
Tx of SCC
Surgical excision - most successful
Radiation therapy - best when combined w surgery
Cryosurgery /electrosurgery
Intralesional chemo
Tropical imiquimod
Cutaneous lymphoma
Rare in cats/dogs
Dogs - presentation is highly variable and mimics other dermatoses
Also called cutaneous epitheliotrophic T cell lymphoma, cutaneous lymphosarcoma
Skin lesion of cutaneous lymphoma
Erythema
Plaques
Erosion/ulcer
Mucosal lesion
DX of cutaneous lymphoma
SKIN BIOPSY
Which lesions??
- depigmented lesions
- lesions w loss of architecture
- erythematous and scaly lesions
- plaques or nodules
NEVER biopsy entirely ulcerated lesions
TX of cutaneous lymphoma
GRAVE prognosis
6-9m
Treatment is only palliative
REFER for recommended treatment
