Approach to alopecia 2

Question 1

What is the pathogenesis of non-inflammatory spontaneous alopecia?

Answer 1

When there is a problem with stimulators or formation of hair itself

Question 2

What are the non-inflammatory conditions of hair follicle arrest?

Answer 2

*Endocrinopathies
*Alopecia X
*Telogen defluxion
*Paraneoplastic alopecia
*Cyclical flank alopecia
*Post-clipping alopecia
*Injection alopecia

Question 3

What are non inflammatory conditions of hair synthesis defects?

Answer 3

*Congenital alopecia
*Pattern alopecia
*Follicular dysplasia
*CDA / BHFD
*Anagen defluxion / effluvium
*Sebaceous adenitis

Question 4

What are the 3 phases of hair cycle?

Answer 4

*Anagen
*Catagen
*Telogen

Question 5

What is anagen?

Answer 5

Growing phase of hair

Question 6

What is catagen?

Answer 6

Transition phase with regression of the lower part of the hair follicle

Question 7

What is the telogen phase?

Answer 7

*Quiescent / resting phase

Question 8

What hormone promotes hair growth?

Answer 8

Thyroid hormone

Question 9

What hormones suppress hair growth?

Answer 9

Oestrogen
Glucocorticoids

Question 10

What are the clinical features of endocrinopathies leading to alopecia?

Answer 10

*Symmetrical to generalised alopecia - bilateral alopecia (inside out)
*Dull and dry coat (lack of thyroid)
*Scaling
*Comedones
*Hyperpigmentation
*Atrophic skin
*Poor wound healing
*Post-clipping alopecia

Question 11

What causes atrophic skin?

Answer 11

Cushings - hyperadrenocorticism = thinning of epidermis = vessels seen through skin

Question 12

What does cushings do considering hair growth?

Answer 12

Blockade of telogen to anogen (stop hair growth)

Question 13

What does hyperadrenocorticism cause?

Answer 13

*Truncal alopecia
*Comedones - black head
*Skin atrophy and striae (wrinkles)
*Prominent blood vessels
*Calcinosis cutis - calcium build up
*Cats – fragile skin

Question 14

What does calcinosis cutis start as? Where is it located?

Answer 14

*Start as small dorsal neck
*Seen on dorsal neck

Question 15

What does hypothyroidism cause?

Answer 15

*Truncal and extremity alopecia
*Myxoedema ‘tragic’ facial expression
*Weight gain
*Lethargy
*Heat seeking

Question 16

What does hyperestrogenism cause?

Answer 16

Promotes decreased hair growth

Question 17

What can sertoli cell tumour cause?

Answer 17

Hyperpigmentation of genital area
Hyperestrogenism = feminisation + decreased hair growth

Question 18

What is telogen defluxion?

Answer 18

*Sudden loss of hair
*Occurs 1-3 months post stress incident
-pregnancy, lactation
-severe illness
-shock , surgery
*Shed as new hair develop

Question 19

What is anagen defluxion?

Answer 19

*Sudden hair loss
-chemotherapy
-severe illness
*Damage to growing hair/follicle
*Patchy to complete hair loss
*loss of whiskers

Question 20

What can cause feline paraneoplastic alopecia?

Answer 20

*Pancreatic + bile duct carcinomas

Question 21

What is alopecia X?

Answer 21

Alopecia of unknown cause

Question 22

What is the rule with recurrent flank alopecia?

Answer 22

*More it occurs less chance of hair growing back
*Seasonal + restricted to flanks

Question 23

What is a concern with congenital alopecia + hairless breeds?

Answer 23

Hair follicles can get blocked - can lead to bacterial infection

Question 24

what can be done with pattern alopecia?

Answer 24

Nothing can be done - owners will be concerned

Question 25

What occurs with follicular dysplasia?

Answer 25

Abnormal hair in hair follicles keep falling out
Progressive hair loss

Question 26

What occurs with black hair follicle dysplasia?

Answer 26

*Black hairs don’t form properly - v friable + fracture easily
*More they fracture = more they fall out

Question 27

What does colour dilution alopecia cause?

Answer 27

*Dilute colour coats - blue / fawn
*Macromelanosomes - melanin clumping = hair fragility
=hair loss + scaling

Question 28

How do you treat hair synthesis defects?

Answer 28

*Avoid damage to coat
*High quality nutrition
*Gentle anti scaling shampoos
*Prevent / treat secondary bacterial infections
*Protect from sun