dermpath alopecia

Question 1

examples of:
- Non neoplastic/tumor
- Non inflammatory
> diseases in these categories - what types of disorders, generally?

Answer 1

• Follicle (Alopecia) disorders
• Collagen and matrix disorders
• Keratinisation disorders
• Physicochemical disorders
• Congenital blistering disorders

Question 2

The Language of Skin: Alopecia, hypotrichosis

Answer 2

• Alopecia is a loss of hair. It may be partial or complete. It is very common.
• Hypotrichosis is a congenital lack of hair. It is very rare.
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  Alopecia = mange in fox; Alopex = fox

Question 3

Alopecia often leads to….

Answer 3

Hyperpigmentation

Question 4

Alopecia
Is it a disease of:

Answer 4

◼ Hair production/Hair follicle (primary alopecia) or
◼ Other disease (secondary alopecia)

Question 5

Biopsy of alopecic disease
- what should we do in the case of alopecia?

Answer 5

◼ Do clinical dermatological examination (‘dermatology due diligence’)
> Trichogram - look at hairs under the microscope
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Biopsy
◼ Normal area
◼ Alopecic area
◼ Border region
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◼ Biopsy will direct you to general area ie ‘endocrine alopecia’.

Question 6

Biopsy report – terminology of hair cycle

Answer 6

• Anagen - active follicle
  > catagen - regressing follicle
  > telogen - resting follicle with hair
  > exogen - release of club hair
• kenogen - resting follicle with no hair club
  > anagen…….
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• some animals eg. some sheep and goats do not go through this cycle

Question 8

Alopecia:
Pathogenesis; Primary alopecia
- what types are there?
- examples?

Answer 8

Primary alopecia (Disease of hair follicle or hair)
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Congenital diseases (abnormal follicles)
◼ Examples
> Hairless breeds (Xolo, Chinese Crested, Sphynx cat)
> Pattern alopecia
> Colour dilution alopecia
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Acquired diseases (failure of hair cycle)
◼ Hormone deficiency or excess
> adrenal, thyroid, GH, castration, sex hormone.
◼ Breed associated
> Alopecia of plush coated breeds (alopecia X)
> Canine recurrent flank alopecia
◼ Metabolic
> Paraneoplastic (pancreatic carcinoma, cats)

Question 9

Alopecia
Pathogenesis; Secondary alopecia
- casues, broadly

Answer 9

◼ Disease outside the hair follicle
> Normal hair broken off
=> Pruritus – breaks off normal hair
=> Pilotrichomania
◼ Scarring destroys follicles
◼ Inflammatory skin disease
> folliculitis, furunculosis, sebaceous adenitis