Keratinization Diseases Flashcards
Which breeds are predisposed to primary seborrheic dermatitis (inherited disorder of epidermal hyperproliferation)?
1) American Cocker Spaniels
2) English Springer Spaniels
3) West Highland White Terriers
4) Bassett hounds
Also Irish setters, Doberman pinschers, Chinese Shar-Peis, dachshunds, Labrador retrievers, GSD)
Which eicosinoids stimulate DNA synthesis in basal cell layer to induce epidermal proliferation?
Leukotriene B4 (LTB4) and Prostaglandin E2 (PGE2)
Which shampoo ingredients are the best “degreasers”, but also increase TEWL?
Tar, benzoyl peroxide (+/- sulfur), selenium sulfide
Which breeds develop vitamin A responsive dermatosis?
Cocker spaniels
Labrador retreiver
Mini schnauzer
others
(Different version ~pruritic~ in gordon setters)
Clin signs: comedones, hyperkeratotic fronds, ceruminous otitis. Follicular plugging
A 5 yo MN cocker spaniel presents with multiple comedones, follicular plugging, and hyperkeratotic plaques with surface fronds on his ears. Diagnosis?
Vitamin A responsive dermatosis
Where on the body does sebaceous gland dysplasia start?
Head, pinnae, dorsum
RARE DZ
Which type of diets has been associated with feline seborrhea sicca?
Low fat (weight reduction, hepatic lipidosis)
Which breed develops ear margin dermatosis (follicular casts, scale)
Dachshunds
(associated w/sleeping next to heat sources?)
What adnexa are hyperplastic in canine tail gland hyperplasia?
1) Sebaceous glands
2) Circumanal glands (esp when androgen levels are high!!)
If a castrated/spayed dog develops tail gland hyperplasia, what organ should you evaluate?
Adrenal gland
Possible functional tumor, altered sex hormone levels
Which adnexa are associated with stud tail in cats?
Sebaceous and epitrichial (apocrine) sweat glands
-Catteries, where cats can’t groom appropriately
-Not just intact males
What is the pathogenesis of thymoma associated exfoliative dermatitis in cats?
Thymoma activates autoreactive CD8+ T cells, that act on epithelial cells
In which cats is leukotrichia seem with thymoma associated exfoliative dermatitis?
Orange cats
Where on body does exfoliative dermatitis begin in cats w/thymoma?
Head/pinnae, the progress down the back
*Also develop clawfold seborrhea
What histopath findings are associated with thymoma associated exfoliative dermatitis in cats?
-Cell-poor to cell-rich interface dermatitis with CD3+ or CD8+ lymphocytes
-Hydropic degeneration of basal keratinocytes
-Apoptotic keratinocytes throughout epidermis
-Mural interface folliculitis
-Sebaceous adenitis
-Severe laminar orthokeratotic hyperkeratosis
What is the treatment of choice for nonthymoma-associated exfoliaitve dermatitis?
Immunosuppressive steroid, atopica
In addition to exfoliative dermatitis, what other paraneoplastic syndromes have been reported in cats?
1) Myasthenia gravis
2) Erythema multiforme
3) Multifocal noninflammatory alopecia
4) Pemphigus
5) Myocarditis
6) Polymyositis
7) Granulocytopenia
*Likely also immune mediated from abnormal maturation/selection of T cells in neoplastic thymus
Which body regions are SPARED in large plaque parapsoriasis (1 dog, 1 cat)? What is the treatment?
Clin signs: widespread erythematous, scaly plaques that SPARE the head, pinnae, and distal limbs
Tx: Immunosuppressive GC
Which internal malignancies are associated with paroxysmal cutaneous flushing? (Red skin d/t vasodilation from vasoactive compounds)
1) Carcinoid syndrome (GI tumor of enterochromaffin cells OR pulmonary adenocarcinoma)
2) MCT
3) Pheochromocytoma
4) Drug reaction
Why can steroids be beneficial in greasy dogs?
Atrophic effects on epidermis and sebaceous glands