How are immune-mediated skin disorders diagnosed?
Histopathology of multiple biopsies
Label these layers
A: Stratum corneum
B: Stratum lucidum
C: Stratum granulosum
D: Stratum spinosum
E: Stratum basale
Cats Love Going Sun Bathing (Daily)
What are the 2 first-choice immunosuppresive drugs to treat immune-mediated skin disorders?
_______ ______ is a vesiculobullous to pustular group of disorders of the skin or mucus membranes characterised by the loss of cohesion between keratinocytes, known as _______.
What is the benign form of pemphigus? Which breeds are predisposed? What are the classical clinical signs and where do they occur?
Collies and GSD
Erythema, pusular dermatitis of face and ears
Transient lesions (oozing crusts, scales, alopecia, eorsions, epidermal collarettes)
Depigmentation of nose
What are the differential diagnoses for pemphigus erythematosus?
Facial pemphigus foliaceus
Zinc responsive dermatitis
T?F: Sun avoidance and systemic glucocorticoids or cyclosporin are the accepted treatments for pemphigus erythematosus.
False, sun avoidance and TOPICAL glucocorticoids or cyclosporine
The most common immune-mediated condition is ______ ________. The major antigen is the adhesion molecule ________.
Where are lesions typically found in a dog with pemphigus foliaceus? Cats?
Dogs: Starts at face and ears, commonly involves feet, clawbeds, footpads and groin
Cats: Nail beds, nipples
Also nasal depigmentation
Where does cellular infiltration in pemphigus foliaceus occur? Which skin layers loss adhesion in pemphigus vulgaris and bullous pemphigoid?
Foliaceus: Between stratum corneum and granulosum
Vulgaris: Stratum spinosum and basale
Bullous pemphigoid: Epidermis and dermis
Where is the most common lesion location for an animal with pemphigus vulgaris? Where are cutaneous lesions common? What is the claw bed lesion?
Which other condition causes lesions in these areas?
Oral cavity (75-90% have lesions in mouth)
Axillae and groin
Ulcerative parochyia (clawbeds)
What drugs are used to treat pemphigus vulgaris?
High dose prednisolone an azathioprine PO
What condition involves autoantibodies against antigens of the basal cell hemidesmosomes of the skin and mucosa? What drugs predispose to this condition?
Sulphonamides, Penicillins, Furosemide
Which cells predominate in lupus erythematosus? Which specifically in DLE and SLE?
Damage to which cells activate T cells in DLE and what do the damaged cells have high levels of? What type of antibody is often formed?
ANA (Anti-nuclear antibody)
Pemphigus vulgaris can involve antibodies reacting against a certain molecule, what is this molecule and in what species is it found?
("V" (vulgaris) rhymes with "Three")
What are some breeds predisposed to DLE? What are the lesions?
Shetland sheepdogs, Siberian huskies, Brittany spaniels, German shorthaired pointers
Lesions: Depigmentation, erythema, scaling of nose, progress to erosions, ulceration and crusting
What part of the skin is thickened in DLE due to cellular infiltration?
What clinical signs occur in dogs with SLE? Is there a sex prediliction in dogs or cats?
Alopecia, erythema, vesciculobullous to ulcerative lesions
Dogs- males over-represented
Cats- no sex prediliction
Your canine patient with SLE has developed glomerulonephritis. What do you expect and what is the prognosis?
Progressive renal failue
What is the drug that most commonly causes cutaneous adverse drug reactions? What does it mean if this reaction is idiosyncratic?
Idiosyncratic: unpredictable, dose-independent, related to host immune system (opposite of predictable reaction which is drug- and dose-dependent)
Your patient acutely develops erythematous macules which have spread peripherally and cleared centrally. There are also urticarial plaques. Lesions are primarily on the ventrum, axillae, and groin. What type of degeneration is occuring and what is this condition called? How is it treated?
Hydropic degeneration (all levels of epidermis)
Tx: Eliminate trigger, wait for it to spontaneously regress.
What will a skin biospy from an animal with toxic epidermal necrolysis reveal?
Full-thickness epidermal nercolysis
What do the lesions that characterize vasculitis look like and where do they occur?
Purpura, wheals, edema, papules, plaques, nodules, alopecia, scarring, necrosis and ulceration (punched out ulcers)
Extremities- paws, pinnae, lips, tail, scrotum, oral mucosa
Other than determining the underlying disease, what drugs are used to treat vasculitis?
Pentoxifylline (increases erythrocyte flexibility and reduces inflammation.)
Immunosuppressive and immunimodulatory drugs
What 3 conditions commonly cause seborrhea, crusts or scales WITH pruritus? What if there is no pruritus?
Allergies (FAD, AD, FA)
Parasites (sarcoptes, cheyletiella)
Infections (pyoderma, malassezia) *+/- pruritus*
No pruritus: demodicosis, dermatophytosis, endocrine diseases (hypothryoid, HAC, alopecia X)
What is the difference between syndrome 1 and syndrome 2 of zinc-responsive dermatosis?
Syndrome 1 is decreased capacity to absorb zinc from GIT
Syndrome 2 is RARE and caused by dietary deficiency
What breeds get breed-related zinc-responsive dermatosis?
What clinical signs are associated with zinc-responsive dermatosis? Where do they occur and when do they start?
Pruiritus and scales/crusts
Mouth, chin, eyes, ears, elbows, pressure points, scrotum, prepuce, vulva
Signs begin around 1-3yrs of age
What are some speculated causes of sebaceous adenitis?
Inherited sebaceous gland destruction
Cell-mediated immunological rxn
Defect in keratinization/obstruction of sebaceous ducts
Abnormal lipid metabolism