Hair loss

Question 1

What stage of growth are most hairs in?

Answer 1

anagen (>80%)

Question 2

How is hair growth regulate? 4

Answer 2

• NUTRITION - and metabolic ddiseases
• CENTRAL SYSTEMIC HORMONES - TH, GCs, sex hormones, IGF1, PRL, melatonin
• REGIONAL - differential response to mediators
• LOCAL - hormones, mediators, growth factors, cytokines

Question 3

Differentiate alopecia and hypotrichosis

Answer 3

ALOPECIA = baldness, absence of hair which is normally present, loss of hair
HYPOTRICHOSIS - congenital alopecia or paucity of hair

Question 4

How can the problem of hair loss be define?

Answer 4

Primary alopecia versus traumatic hair loss (due to pruritus and other mechanical factors)

Question 5

What are the 4 main categories of causes of hair loss?

Answer 5

• trauma
• follicle destruction
• disruption of hair growth
• deformation of hair follicle

Question 6

What should you do if a cat presents with symmetrical alopecia?

Answer 6

Probably self-inflicated unless proven otherwise (owners likely to deny this) so work up as self-trauma

Question 7

How do you refine the problem of hair loss?

Answer 7

Inflammatory versus non-inflammatory

Question 8

What are the 2 types of inflammatory hair loss?

Answer 8

1. ) dermal inflammation with a hair follicle as a bystander (Leishmania)
2. ) dermal inflammation that specifically targets a hair follicle (Demodex, Dermatophytes, bacterial folliculitis)

Question 9

What are the 2 types of non-inflammatory hair loss?

Answer 9

1. ) dysfunctional hair cycle

2. ) problem with hair follicle structure

Question 10

How do endocrine disorders generally affect hair growth?

Answer 10

arrest hair growth in the telogen phase

Question 11

What are 3 classic signs of Cushings in dogs?

Answer 11

• mm loss
• thin skin
• distended abdomen

Question 12

What is alopecia X?

Answer 12

• hair growth of unknown origin, possibly endocrine but no consistent hormonal abnormality and no consistent reversal of abnormality on successful treatment
• some evidence of abnormal adrenal steroidogenesis and some response to steroidogenesis inhibitor but unknown significance
• may only be a cosmetic problem

Question 13

What are the 4 main categories of acquired non-traumatic alopecia?

Answer 13

• endocrinopathies
• coat colour-linked
• miscellaneous hair cycle/growth problems
• other (rare)

Question 14

What is (recurrent) flank alopecia?

Answer 14

• hyperpigmentation when hair is lost
• usually dogs healthy, only cosmetic, remember sunscreen
• breeds: Airedales, Boxers, Bulldogs, Schnauzers, Rhodesian ridgebacks

Question 15

What is the cause of pattern alopecia?

Answer 15

(i. e. this is alopecia in specific regions)
- due to miniaturisation of hair shafts
- a type of follicular dystrophy/dysplasia

Question 16

How do you work up a case of alopecia that you suspect is inflammatory (i.e. infectious)?

Answer 16

diagnostic tests to investigate demodecosis, bacterial folliculitis (staph) and dermatophytosis. If not consider endocrine diseases. Then look up miscellaneous alopecias (especially breed-related).

Question 17

Are inflammatory or non-inflammatory skin diseases most common in general practice?

Answer 17

inflammatory