10- Alopecia Flashcards
Define alopecia
loss of hair
Define primary alopecia
failure of hair to grow normally
Define secondary alopceia
hair grows normally but subsequently damaged or lost
define true alopecia
direct damage to hair follicle unit–> loss of whole hair follicle unit
Define apparent alopecia
hair shaft damaged but not lost from hair follicle unit
hair cropped short
What phases of the hair cycle does primary alopecia affect and how
Anagen- growth phase - lack of stimulation or abnormal growth factors
Telogen- resting phase- elongation of this phase
What is the most common cause of alopecia
Folliculitis –> hair follicle unit is damaged
What are 2 common infections which present with alopecia
Demodicosis- dogs
Dermatophytosis- cows, horses, cats
superficial pyoderma
What are the 3 distributions of alopecic lesions
localised
multifocal/diffuse patchy
symmetrical/ diffuse
In guinea pigs what can cause alopecia
In entire female guinea pigs - ovarian neoplasia
how can sertoli cell tumours cause alopecia in entire male dogs
oestrogen production –> alopecia
What diagnostic test is used to know if alopecia is true or apparent
Trichogram
Name 2 initial tests that are performed on an alopecic patient
Skin scraping (for demodicosis)
Dermatophyte investigation- microscopy/ culture/ woods lamp
Trichogram
If your initial tests come back without a diagnosis what further tests could you do for an alopecic patient?
Cytology - pyoderma (will have an underlying disease…)
Skin biopsy:
- Folliculitis, autoimmune, atrophic change- if these suspected
Endocrine changes- if suspected