Pruritis in Dogs Flashcards
CAD
Pathogenesis of canine atopic dermatitis (CAD)
- IgE process
Genetic predisposition of a defective skin barrier -> easy penetration of environmental allergens -> Langerhans cells pick up the allergens/antigens and present to naive T-lymphocytes -> -> IgE antobodies produced & bind to mast cells -> degranulation & release of histamine => pruritis and inflammation
TEWL = Trans-Epidermal Water Loss (lesional > non-lesional) -> diminshed hydration barrier in the epidermis
or
Ultra-Structure = disorganized corneocytes and lipid lamellae
CAD
What are Regulatory T-Cells (Tregs)
cells that act as “check and balances” – act to prevent an overreactive immune system
CAD
Characteristic regions affected in CAD?
Dog: perioccular region, muzzle, neck, paws
Cat: ventral abdomen, axillary region, muzzle, neck, medial aspect of pinnae, paws
Dog: almost NEVER the dorsal trunk!
CAD
Common lesions of CAD?
Alopecia, erythema, hyperpigmentation, saliva staining
CAD
How is CAD diagnosed?
After other pruritic diseases have been ruled out!
- CAD = a CLINICAL DIAGNOSIS
- Serum allergy tests and intradermal tests ARE NOT RELIABLE TOOLS TO DIAGNOSE!
food allergy
What is the only reliable diagnostic tool for Cutaneous adverse food reaction?
elimination diet
8-week duration: >90% diagnosed
also: a lack of GI signs does NOT rule out
What are hydroylzed protein diets?
food does not contain intact proteins, but instead only the peptides (peptides are propsed to be non-antigenic)
What is the goal of allergen-specific immunotherapy?
Injection of the allergen into the patient with goal of de-sensitization
Trial may be up to 12 months
Common drugs given for managing CAD?
CAD cannot be cured! Tx = life-long, management = goal
Lokivetmab: mononuclear antibody that neutralized IL-31 ( a pruritogenic cytokine)
Glucocorticoids: ineffective as sole therapy in most canine AD
