Feline cutaneous reaction patterns and pruritus Flashcards
Describe the pathogenesis of feline cutaneous reaction patterns
- skin barrier dysfunction
- immune dysregulation and allergen sensitisation
- environmental factors
- stress
- microbes
What is feline atopic syndrome
Allergic disease associated with environmental allergens, food allergy and asthma that may be associated with IgE antibodies
What is feline atopic skin syndrome?
Inflammatory and pruritic dermatitis involving a spectrum of non-specific cutaneous reaction patterns (CRPS), that may be associated with IgE to environmental allergens
What is a food allergy?
Any disease, including FASS, attributable to immunological reactivity to ingested food items
Which 2 cells are involved in a feline atopic syndrome response?
Eosinophils
Lymphocytes
What is the main difference between extrinsic and intrinsic feline atopic syndrome?
Extrinsic disease: pathogenesis involves IgE and is demonstrable (via allergy testing)
Intrinsic disease: same clinical signs, no demonstrable IgE
Describe the typical features of a history takes from a patient with feline atopic skin syndrome
- Young age at onset (6m–3y)
- Presence of pruritus
- Absence of contagion
- Response to corticosteroids
What are the characteristics of FASS lesions?
- Pruritis
- Erythematous papules
- Excoriations
- Lichenification
- Hyperpigmentation
Where are lesions distributed in FASS?
- Ears
- Eyes
- chin
- footpads
- ventral abdomen
- tail base
Before FASS is conformed as the diagnoses what 4 differentials must be eliminated?
- Flea/flea allergy
- Parasites
- infections
- food allergy
How can pruritis be confirmed in the cat when it is not observed?
Look for evidence of self-trauma
- Linear excoriations
- Short, spikey hairs on examination
- Vomiting fur balls
- Hair in faeces
- Embedded hair in gingival sulci and/or tongue
- Clumps of hair in cat’s environment
- Trichogram: broken/frayed tips
What are the two causes of non-pruritic self induced alopecia?
Anxiety
Pain e.g. uti, orthopaedic
What are the signs of self-induced alopecia?
- Non inflamed (macroscopically)
- Areas cat can reach (symmetrical)
- Ventral abdomen, lateral thorax, caudal thighs
- Often linear
How is miliarry dermatitis characterised?
- Multiple crusted papules, very pink
- Dorsum
- (Caudomedial thighs, ventral abdomen)
Which 3 lesions make up an eosinophilic granuloma complex?
- Eosinophilic plaque
- Eosinophilic granuloma
- Indolent ulcer
What is an eosinophilic plaque? Where do they occur?
- Highly pruritic
- Raised, alopecic, erythematous, eroded to ulcerated plaque
- Abdominal and inguinal skin
- Medial and caudal thighs
- Interdigital skin
- Neck
What is an eosinophilic granuloma?
- Pruritus variable
- Alopecic, raised plaque/nodule
- Intact skin or eroded-ulcerated: ulcerated lesions central white accumulations
Where do eosinophilic granulomas occur?
- Caudal thighs
- Hard/soft palate +/- necrosis
- Swelling of chin (asymptomatic)
What is an indolent ulcer?
- Non-pruritic
- Non-painful
- Well circumscribed, red/brown ulcer with raised border
- Found on the upper lip
Give some examples of diagnostic tests that allow ruling out of differential diagnosis for FASS
- Direct/indirect impression smear cytology
- Flea combing
- Scale examinations
- Skin scrapings
- Trichography
- Dermatophyte culture
- Trial treatment – Demodex gatoi
Describe a flea eradication trial
Treat all cats and contacts with flea treatment
Trial lasts 6-8 weeks
Use an adulticide with a rapid speed of kill
Describe a food elimination diet
- lasts 8-12 weeks
- Novel home cooked diet
- Commercial novel hydrolysed or single protein diet
- Re-challenge with previous foods over two weeks
- Re-stabilise with trial diet confirms diagnosis
What are the 4 components of multimodal management of FAS?
- Skin barrier care
- Anti-inflammatories to control skin inflammation
- Allergen avoidance
- Control flare factors e.g. regular Ectoparasiticides, reduce stress
What are some recommended treatments for FAS?
- systemic glucocorticoids
- ciclosporin
- topical glucocorticoids
What is the purpose of allergen specific immunotherapy?
Reduce flares associated with exposure to environmental allergens
What factors need to be considered when treating FAS?
Patient factors: - severity of disease - general health status - home environment - treatment administration (temperament) Client factors: - financial constraints - treatment administration (time, physical constraints)
Name 2 glucocorticoid drugs used as anti-inflammatories/ immunomodulators in FAS
Prednisolone
Dexamethasone
What are some of Favrot’s criteria for FASS diagnosis?
- at least 2 body sites affected
- 2/4 of the feline cutaneous reaction patterns
- symmetrical alopecia
- erosions/ulcerations on the chin
- no lesions on the rump
- pruritis at onset
