Approach to SA Scaling Flashcards
(23 cards)
Definition of scale
A thick, dry flake of skin
Which layer of the skin is necessary for maintaining the skin hydration and to protect from external insults
The stratum corneum
What happens to corneocytes in exfoliative dermatitis
Cornecoytes detach in large clusters, or scales
3 causes of exfoliative dermatitis in the dog
Excessive production of the stratum corneum
Lack of destruction of the stratum corneum
Defective formation or removal of the protective hydrolipidic film
4 causes of Excessive production of stratum corneum
- Congenital (e.g. ichthyosis)
- Reaction to damage from outside (physical trauma, ectoparasite infestations, bacterial/yeast infections)
- Reaction to damage from inside (inflammatory infiltrates)
- Metabolic diseases (Zinc-responsive dermatosis, hepatocutaneous syndrome, generic dog food dermatosis)
3 causes of Defective production of hydrolipidic film (sebaceous gland damage)
Sebaceous adenitis
Leishmaniasis
Cushing syndrome
Does Leishmaniosis cause thick adherent scales
Yes
Does Sebaceous adenitis cause thick adherent scales
Yes
Does Bacterial/yeast infections
cause thick adherent scales
No. Small, non-adherent dry scales
Does Epitheliotropic lymphoma cause thick adherent scales
Yes
Does Metabolic diseases (localised)
cause thick adherent scales
Yes
Does Ectoparasite infestations
cause thick adherent scales
No. Small, non-adherent dry scales
Does frequent bathing
cause thick adherent scales
No. Small, non-adherent dry scales
Does Aggressive grooming products
cause thick adherent scales
No. Small, non-adherent dry scales
What diagnostic procedure should be done FIRST when investigating scaling
Always perform a deep skin scraping (Demodex mites occasionally can give a «dry and desquamative» form of infestation
Differential list if Thick, adherent scales, head or generalised
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
Differential list if Lesions are periocular, perilabial, margins of ear pinnae or paw pads
Possible metabolic disease (Zinc-responsive derm.)
Skin biopsy often necessary
CBC + biochemistry (+ abdominal ultrasound) for older animals
4 causes of exfoliative dermatitis in cats
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)
What is the paraneoplastic syndrome that involves thick, adherent scales in cats
Thymoma-associated exfoliative dermatitis
4 causes for cats to have small dry scales at the trunk area
Cheyletiella
Dermatophytosis (Ringworm)
Poor grooming
Metabolic diseases
Cause of cat to have small dry scale at tip of pinnae
solar dermatosis (non pigmented areas)
Cause of cat to have small dry scale at weight bearing points
callus, possible allergy
How to rule out dermaphytosis (ringworm)
Trichoscopic examination
Wood’s lamp examination
Fungal culture
