Approach to SA Scaling

Question 1

Definition of scale

Answer 1

A thick, dry flake of skin

Question 2

Which layer of the skin is necessary for maintaining the skin hydration and to protect from external insults

Answer 2

The stratum corneum

Question 3

What happens to corneocytes in exfoliative dermatitis

Answer 3

Cornecoytes detach in large clusters, or scales

Question 4

3 causes of exfoliative dermatitis in the dog

Answer 4

Excessive production of the stratum corneum
Lack of destruction of the stratum corneum
Defective formation or removal of the protective hydrolipidic film

Question 5

4 causes of Excessive production of stratum corneum

Answer 5

1. Congenital (e.g. ichthyosis)
2. Reaction to damage from outside (physical trauma, ectoparasite infestations, bacterial/yeast infections)
3. Reaction to damage from inside (inflammatory infiltrates)
4. Metabolic diseases (Zinc-responsive dermatosis, hepatocutaneous syndrome, generic dog food dermatosis)

Question 6

3 causes of Defective production of hydrolipidic film (sebaceous gland damage)

Answer 6

Sebaceous adenitis
Leishmaniasis
Cushing syndrome

Question 7

Does Leishmaniosis cause thick adherent scales

Answer 7

Yes

Question 8

Does Sebaceous adenitis cause thick adherent scales

Answer 8

Yes

Question 9

Does Bacterial/yeast infections
cause thick adherent scales

Answer 9

No. Small, non-adherent dry scales

Question 10

Does Epitheliotropic lymphoma cause thick adherent scales

Answer 10

Yes

Question 11

Does Metabolic diseases (localised)
cause thick adherent scales

Answer 11

Yes

Question 12

Does Ectoparasite infestations
cause thick adherent scales

Answer 12

No. Small, non-adherent dry scales

Question 13

Does frequent bathing
cause thick adherent scales

Answer 13

No. Small, non-adherent dry scales

Question 14

Does Aggressive grooming products
cause thick adherent scales

Answer 14

No. Small, non-adherent dry scales

Question 15

What diagnostic procedure should be done FIRST when investigating scaling

Answer 15

Always perform a deep skin scraping (Demodex mites occasionally can give a «dry and desquamative» form of infestation

Question 16

Differential list if Thick, adherent scales, head or generalised

Answer 16

History of travel to/from an endemic area: Leishmania serology
If negative serology => SKIN BIOPSY (sebaceous adenitis?)
If bacterial infection treat topically with chlorhexidine 4% 2 weeks before the biopsy

Question 17

Differential list if Lesions are periocular, perilabial, margins of ear pinnae or paw pads

Answer 17

Possible metabolic disease (Zinc-responsive derm.)
Skin biopsy often necessary
CBC + biochemistry (+ abdominal ultrasound) for older animals

Question 18

4 causes of exfoliative dermatitis in cats

Answer 18

Congenital
Reaction to external damages (friction, parasites, dermatophytes)
Reaction to endogenous insults (PF, lymphoma, EM, Thymoma associated)
Metabolic (hepatocutaneous syndrome, obesity, DM, renal failure, hyperthiroidism)

Question 19

What is the paraneoplastic syndrome that involves thick, adherent scales in cats

Answer 19

Thymoma-associated exfoliative dermatitis

Question 20

4 causes for cats to have small dry scales at the trunk area

Answer 20

Cheyletiella
Dermatophytosis (Ringworm)
Poor grooming
Metabolic diseases

Question 21

Cause of cat to have small dry scale at tip of pinnae

Answer 21

solar dermatosis (non pigmented areas)

Question 22

Cause of cat to have small dry scale at weight bearing points

Answer 22

callus, possible allergy

Question 23

How to rule out dermaphytosis (ringworm)

Answer 23

Trichoscopic examination
Wood’s lamp examination
Fungal culture