Hair Loss Flashcards
What are the stages of the hair growth cycle?
Anagen
Catagen
Telogen
What mechanisms regulate hair growth?
Nutrition
Systemic hormones
Regional responses to mediators
Local hormones
Define alopecia and hypotrichosis
A - Absence of hair where it is normally present, hair loss
H - Congenital alopecia, insufficient hair growth
What are the 4 principles of mechanisms of hair loss?
Traumatic removal
Damaged follicle
Hair cycle arrest
Malformed/atrophic follicles
How can alopecia be diagnosed as being caused by traumatic hair loss?
History
Clinical exam - Hair pluck
Which species suffers symmetrical alopecia due to pruritus?
Cats
What are inflammatory causes of alopecia?
Folliculitis:
- Demodex
- Staph infection
- Dermatophytes
What are non-inflammatory causes of alopecia?
Problems of hair follicle structure or function
What disorders that can result in dysregulation of the hair cycle?
Hyperoestrogenism
Hypothryoidism
Hyperglucocorticism
Telogen effulvium
Where in the hair cycle is arrest most likely to happen?
Telogen => anagen
Outline the characteristics of alopecia X..
Unknown aetiology
No other systemic signs
Hair is unaffected on head and limbs
No consistent treatment
What clinical signs is likely to occur in in an endocrinopathy that causes alopecia?
Changes in pigmentation of the skin
What are the causes of hair cycle arrest?
Endocrinopathies
Alopecia X
