4.23.1.14 Allergic skin disease (1) Pathogenesis and presentation.pptx

Pruritus Allergic skin disease workshop  Learning objectives – all sessions  Describe and explain the history and clinical signs of allergic skin disease (ASD) in dogs and cats, using prior immunological knowledge  Choose appropriate diagnostic tests to make a final diagnosi...

Pruritus Allergic skin disease workshop  Learning objectives – all sessions  Describe and explain the history and clinical signs of allergic skin disease (ASD) in dogs and cats, using prior immunological knowledge  Choose appropriate diagnostic tests to make a final diagnosis of ASD, considering the usefulness and difficulties of serological and intradermal testing  Select appropriate treatments for dogs and cats with allergic disease to meet both acute (flare) and chronic treatment needs, considering cost, practicality and efficacy Whole session plan Allergic skin disease (1) Pathogenesis and clinical signs – lecture – 40 min (2) Diagnostic tests for food-induced and environmental atopy – group work – 30 min (3) Treatment options - 40 min (4) Cases – group work – 30 min 2 (1) Pathogenesis and presentation  Learning objectives  Describe and explain the history and clinical signs of allergic skin disease (ASD) in dogs and cats, using prior immunological knowledge  Choose appropriate diagnostic tests to make a final diagnosis of ASD, considering the usefulness and difficulties of serological and intradermal testing  Select appropriate treatments for dogs and cats with allergic disease to meet both acute (flare) and chronic treatment needs, considering cost, practicality and efficacy Whole session plan Allergic skin disease (1) Pathogenesis and clinical signs – lecture (2) Diagnostic tests for food-induced and environmental atopy – group work (3) Treatment options (4) Cases – group work 4 The story so far… Y3 FCP 5  Allergic skin disease Allergy = a condition caused by a hypersensitivity response to allergens Common cause of pruritus in dogs and cats Multifactorial condition Triggers  Environmental allergens  Environmental atopic dermatitis - dog  Feline atopic skin syndrome (FASS) – cat Environmental influences  Foods  Food-induced atopic dermatitis (‘food allergy’)– dog  Feline food allergy (FFA) – cat Allergy  Ectoparasites Immunological Genetic  Flea allergic dermatitis background dysregulation  Insect bite hypersensitivity  Mite hypersensitivity – especially Sarcoptes  Contact allergens  Micro-organisms, e.g. Malassezia hypersensitivity  Drugs Common triggers in bold  Type I hypersensitivity most commonly involved Type Name of Key features hypersensitivity But >1 type of hypersensitivity proposed for I Immediate Cross-linking of IgE molecules on mast some conditions cell surface by allergen  degranulation  Picture is complex and incompletely understood tissue inflammation But all require stages of Sensitisation of individual by repeated exposure to allergen Subsequent exposure  immunologically excessive/inappropriate response  clinical disease Here we will consider Canine atopic dermatitis (CAD) – environmental and food-induced Feline atopic syndrome (FAS) – including feline atopic skin syndrome (FASS), feline food allergy (FFA) Others Contact hypersensitivity Drug reactions Parasitic arthropod hypersensitivity Canine atopic dermatitis (CAD)  Canine atopic dermatitis (CAD) A common chronic, relapsing, pruritic and inflammatory skin syndrome with characteristic clinical features Traditionally associated with IgE antibodies to environmental allergens BUT 