Scaling and Crusting Flashcards Preview

Dermatology > Scaling and Crusting > Flashcards

Flashcards in Scaling and Crusting Deck (32)
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1
Q

Define scale

A

An accumulation of loose cornified fragments of the stratum corneum

2
Q

Define crust

A

Presence of dried exudate on the skin surface

3
Q

What is follicular casting?

A

Thickened stratum corneum around hair shaft

4
Q

What is the most common cause of follicular casting?

A

Demodecosis

5
Q

What is a comedo?

A

Sebaceous gland filled with keratinised debris

6
Q

What can cause comedomes?

A

Demodecosis, endocrine disease or as a primary defect of cornification

7
Q

What is seborrhoea?

A

Flow of sebum

Vague clinical term for scaling/greasy exudation

8
Q

What is seborrhoea sicca?

A

Dry scaling

9
Q

What is seborrhoea oleosa?

A

Oily scaling

10
Q

What is seborrhoeic dermatitis?

A

Greasy, inflamed skin

11
Q

What do defects of cornification refer to?

A

Skin diseases where scaling/follicular casting is a dominant clinical feature

12
Q

What are some causes of secondary defects of cornification?

A

Parasites, infection, nutrition, allergy, neoplasia

13
Q

What are some primary causes of defects of cornification?

A

Idiopathic or genetic defect

14
Q

What is spaniel seborrhoea?

A

Primary defect affecting Cocker Spaniels resulting in increased mitotic rate/decreased turnover time

15
Q

What do skin grafts of animals with spaniel seborrhoea do?

A

Remain hyperproliferative resulting in localised or generalised scaling/casting

16
Q

How is spaniel seborrhoea diagnosed?

A

Exclude primary causes and biopsy

17
Q

What is the treatment for spaniel seborrhoea?

A

Shampoo 2x a week to remove excess scale
Vitamin A (there is a vit A responsive form)
Retinoids (synthetic vit A derivatives) - caution highly teratogenic

18
Q

What is sebaceous adenitis?

A

Sebaceous glands are destroyed causing generalised scaling/casting and varying alopecia as it can interfere with normal hair growth

19
Q

How is sebaceous adenitis diagnosed?

A

Exclude secondary causes and biopsy

20
Q

What is the treatment for sebaceous adenitis?

A

Shampoo, EFA (fatty acids), cyA (cyclosporine not licensed but considered under cascade)
Can use retinoids but teratogenic

21
Q

What is crusting a consequence of?

A

Epidermal inflammation due to a severe oedematous response or marker cellular recruitment

22
Q

What are common triggers of crusting?

A

Physical damage, infection or infestation

23
Q

What are the differential diagnoses for pruritic, steroid-resistant crusting lesions?

A

Scabies, pemphigus, dermatophytosis, cutaneous lymphoma

24
Q

What is the diagnostic plan for pruritic, steroid-resistant crusting lesions?

A

Skin scrapings

25
Q

What is the treatment for scabies?

A

Amitraz weekly for 6 weeks, body clip if long haired, prednisolone 0.75mg/kg SID for 10 days, cephalexin 20mg/kg BID for 3 weeks

26
Q

Why can topical drug treatments fail?

A

Doesn’t reach skin of long haired dogs

Washed off before it can be absorbed in sufficient conc.

27
Q

What are the DDx for dogs with lameness, lethargy, inappetance, PU/PD, weight loss, progressive skin disease and interdigital dermatitis?

A

Superficial necrolytic dermatitis, pemphigous foliaceus, systemic lupus erythematosus, drug eruption, erythema multiforme

28
Q

What are the synonyms for superficial necrolytic dermatitis?

A

Diabetic dermatosis, hepatocutaneous syndrome, metabolic epidermal necrosis, necrolytic migratory erythema

29
Q

What is superficial necrolytic dermatitis?

A

Uncommon erosive, crusting, ulcerative disease which commonly affects the footpads, extremities and periorificial skin of middle-aged and old dogs

30
Q

How is superficial necrolytic dermatitis (SND) diagnosed?

A

Rule out parasites
Haematology and biochemistry
Skin biopsy - pallor (oedema, hydropic degeneration) of upper epidermis, ortho/parakeratotic hyperkeratiosis, superficial dermal infiltration (mononuclear cells)
Ultrasound = diffuse hypoechogenic areas in liver

31
Q

What is the pathogenesis of SND?

A

Seen with hepatic disease or pancreatic glucogonoma

Bile acids and ultrasound may help differentiation of underlying disease

32
Q

What is the prognosis of SND?

A

Poor