Dermatology Flashcards
What are some allergy triggers?
Environmental allergens
Food
Ectoparasites
Contact allergens
Microorganisms
Drugs
What is canine atopic dermatitis?
Common, chronic, relapsing, pruritic and inflammatory skin syndrome with characteristic clinical features.
What are some common environmental allergens?
Dust mites, pollens and moulds
When does environmental canine atopic dermatitis occur?
On re-exposure of an allergen
What pathophysiology occurs on re-exposure to an allergen?
Degranulation of mast cells and production of cytokines from activated T-cells.
What are the 7 points of Favrot’s criteria for environmental CAD?
- Age of onset <3years
- Living mostly indoors
- Glucocorticoid-responsive pruritus
- Non-lesional pruritus
- Affected front feet and/pr pinnae
- Unaffected ear margins
- Unaffected dorsal/lumbar area
What are the clinical signs of uncomplicated environmental CAD?
Erythema, self-induced alopecia, excoriations, primary popular eruption
What common food sources can cause a food allergy in dogs?
Beef, dairy, chicken and wheat
What is feline atopic skin syndrome?
Inflammatory/pruritus skin syndrome likely associated with IgE
Pros and cons of using glucocorticoids for allergies
Pros: Highly effective for inflammation and pruritus, rapid onset (24hrs), inexpensive
Cons: Significant side effect risk
What is oclacitinib (apoquel) licenced for?
Dogs that are a minimum of 1 year old
What is the action of lokivetmab (cytopoint)?
Blocks interleukin-31
Pros and cons of lokivetmab?
Pros: Good safety profile, excellent anti-pruritic, rapid onset, use in dogs of any age, with impaired liver/kidney function and neoplasia
Cons: Dogs only, efficacy may be lost with time, minimal anti-inflammatory effect, rare anaphylaxis
What is ciclosporin licenced for?
Dogs and cats
What is the action of ciclosporin?
T-cell suppressor
What are the challenges with cat allergy management?
- Few licenced products
- Administration of treatments more difficult
- Vet visits more stressful
- Scratching can cause rapid and severe damage
What is the most common bacterial skin infection?
Staphylococcus pseudintermedius
What are signs of a bacterial skin infection?
Focal to multifocal patches of alopecia +/- pustules and crusts.
Most common species of ringworm
Microsporum canis
Indications for mild cases of ringworm
Scale and associated alopecia. Multifocal patches are often circular and typically 4-6cm +/- hyperpigmentation. Follicular casts.
Diagnostic options for ringworm
Woods lamp, trichography, in house DTM, external lab fungal culture +/- PCR
What causes demodicosis?
Demodex mites
Indications of juvenile onset demodicosis
Localised or generalised. Alopecia, scaling, blue-grey hyperpigmentation, comedones, follicular casts +/- superficial bacterial infection
What diseases are follicular casts a common presentation of?
Demodicosis
Dermatophytosis
Sebaceous adenitis
Clinical signs of demodex cati
Comedones, alopecia, erythema, crust and scale
Treatment options for demodex cati
Isoxazolines, selemectin or sarolaner
Breed pre-disposition to sebaceous adenitis
Akitas and poodles
Breed pre-disposition to dermatomyositis
Collies
Main clinical sign of alopecia areata
Rapid hair loss followed by incomplete regrowth of white hair
What is telogen defluxion?
Sudden loss of hair that occurs 1-3 months post-stressful incident.
What is alopecia X?
Primary hair loss follows by complete alopecia and hyperpigmentation
What medications can cause injection alopecia?
Glucocorticoids, vaccines and depot antibiotics
4 hair synthesis defects
- Congenital alopecia
- Pattern alopecia
- Follicular dysplasia
- Anagen defluxion/effluvium
Age range of environmental atopic dermatitis
6 months to 3 years
Typical age of onset of food induced atopic dermatitis
Less than 1 year
Presentation of deep pyoderma
Furunculosis, abscess or cellulitis
Differentials for pinnal margin pruritus
Scabies
Neotrombicular autumnalis
What 3 physiological factors can be associated with otitis?
Temperature, humidity and pH
Normal flora of the otitis externis
Predominantly gram positive cocci and malassezia
Otodecetes cyanotis treatment
Ear cream, cleaner =/- steroids
Consequences of otitis media
Conductive deafness, Horner’s syndrome and vestibular syndrome
Clinical signs of otitis interna
Head tilt to affected side
Spontaneous or rotatory nystagmus
Asymmetrical limb ataxia
Falling
Vomiting +/- anorexia
The four feline cutaneous reaction patterns
Head and neck pruritus
Miliary dermatitis
Bilaterally symmetrical alopecia
Eosinophilic granuloma complex lesions
What is dysbiosis?
Involves imbalance between types of organisms in the microbiome
Canine intertrigo
Skin fold infection
Acute moist dermatitis
Acute lesions caused by skin self-trauma
What is impetigo associated with?
Immature immune system/ immunosuppression
What drugs are contraindicated with deep pyoderma?
Corticosteroids and oclacitinib
What are the risk factors for meticillin-resistant staphylococcal pyoderma (MRS)?
Previous antimicrobial therapy, repeated visits to the vets and invasive procedures
Definition of pruritis
Unpleasant sensation that elicits the desire or reflex to scratch
Biggest cause of feline face, head and neck pruritus
Ectoparasites
Common sites of eosinophilic granuloma complex
Caudal thighs and oral cavity
Minimum length of time for an exclusion diet trial
8 weeks
What is scale?
Presence of flakes and keratin in the hair coat and on the skin
Breed predisposition to Zn-responsive dermatosis
Husky
Key histological finding of Zinc-responsive dermatosis
Hyperkeratosis
Breed pre-disposition of Ichthyosis
Golden retriever
Cutaneous lupus signalment for FDLE and MCLE
FDLE - GSDS - 7 year onset
MCLE - Female GSDs, 6 year onset
Colloquial name for decubital ulcers
Pressure sores
