Non-inflammatory Alopecia

Question 1

T/F: alopecia is typically infectious (folliculitis) but it is not always

Answer 1

True

Question 2

What are the stages in the hair cycle

Answer 2

1) Anagen - growth phase
2) Catagen- transition
3) Telogen- resting
4) Exogen- release/ shedding

Question 3

What are the influeneces of the hair cycle

Answer 3

1) External: photoperiod, ambient temperature, nutrtion
2) Genetic
3) Hormonal
4) Neuronal
5) Immunologic
6) Cellular (mast cells, macrophages)
7) Signaling (growth factors, cytokines)

Question 4

What endocrinopathies cause alopecia

Answer 4

1) Hyperadrenocortisim (spontaneous, atypical, iatrogenic)
2) Hypothyroidism
3) Sex hormone imbalances ( Testicular neoplasia, cystic ovaries, ovary neoplasia, estrogen exogenous supplementation), sex hormone producing adrenal tumors
4) Grown hormone deficiency (pituitary dwarfism)
5) Diabetes mellitus (maybe secondary to bacterial pyoderma)

*skin biopsies not particularly useful for differentiation

Question 5

What might cause sex hormone imbalances leading to alopecia

Answer 5

-Testicular neoplasia (ie sertoli cell tumor)
-Cystic ovaries
-Ovarian neoplasia
-Exogenous supplementation (estrogen)
-Sex hormone producing adrenal tumors (ie progestens)
-Contact with sex hormone topicals used by owners

Question 6

T/F: skin biopsies are not particularly useful for differentiation of endocrinopathy causes of alopecia

Answer 6

True

Question 7

How can hormone imbalances effect the coat

Answer 7

1) Hair follicle cycle abnormalities
-Telogenization of follicles (stuck in resting phase)
-Failure to regrow after clipping
-Hair loss

2) Hanges in hair quality- coarse and frizzy

3) Changes in coat color- bleaching or darkening

Question 8

Alopecia due to hormone imbalances is typically

Answer 8

bilaterally symmetrical truncal/ tail coat thinning

sparing the head and distal extremities

Question 9

What signs might you see of disordered keratinization from hormone imbalances

Answer 9

1) Hyperkeratosis- thickening of stratum corneum
2) Scaling/seborrhea
3) Comedo (black head formation)

non-specific

Question 10

Hair due to hormone imbalance will be

Answer 10

dull, dry, brittle +/- texture and color change

Question 11

changes in hair thickness (atrophy) is seen with

Answer 11

hyperadrenocorticism
excess progestogen exposure
diabetes mellitus

Question 12

alopecia or coat thinning due to hormone imbalances is typically spared at the

Answer 12

head and distal extremities

Question 13

If you see a comedone in a cushing’s patient, why might you also want to diagnostically work the case up more

Answer 13

even though HAC can cause comedones, they are also immunocompromised which demodex could also cause comedones

Question 14

With HAC, you can see cutaneous atrophy, what is that

Answer 14

often first noted in areas of old scars
striae (stretch marks)- ventrum
visible blood vessels
palpably thin
loss of elasticity
calcinosis cutis

Question 15

vascular proliferations often seen in Cushing patients
differential for hemangiomas
might want to biopsy if cushings not diagnosed

Answer 15

Phlebectasia

Question 16

What should you beware of with long-term, daily, low dose prednisone or prednisolone for allergy management, daily budesonide for IBD, and hgiher dose daily or EOD therapy for immune mediated disease

Answer 16

Iatrogenic hyperadrenocorticism

Question 17

Alopecia over the bridging of the nose makes you suspicious for

Answer 17

Hypothyroidism

Question 18

T/F: rat tail hypotrichosis is specific for hypothyroidism

Answer 18

False

Question 19

What are the hypometabolic skin changes seen with hypothyroidism

Answer 19

1) Hyperkeratotic- thickening of stratum corneum (panum and areas of wear)
2) Epidermis normal to thickenined
3) Dermis normal to thickened
+/- mucin accumulation in dermis

Question 20

What are your differentials for paw pad hyperkeratosis

Answer 20

1) Hypothyroidism
2) Zinc responsive dermatosis
3) Superficial Necrolytic Dermatosis (Liver failure)
4) Pemphigus
5) Idiopathic

Question 21

With endocrinopathies, what might you see with response to therapy

Answer 21

May see initial - gets worse before better
1) Increased shedding/exfoliative dermatitis, scaling 3-6 weeks into treatments
2) Initial hair regrowth - often darker

Best normalization of coat/skin associated with optimal control:
-TT4 high normal to slightly supra-normal on BID therapy
-Cortisol normalized

Question 22

How long does it take for the skincoat to get better after treating endocrinopathies

Answer 22

by about 3-6 weeks

Question 23

With treating endocrinopathies, you get the best normalization of coat/skin with

Answer 23

1) TT4 high normal to slightly supra-normal on BID therapy
2) Cortisol normalized

Question 24

Perianal adenomas/adenocarcinomas

Answer 24

excess androgen produced from testicular tumors or adrenals

hyperplasia of circumanal glands and tail glands
-regress after neutering

Question 25

Sertoli cell tumors have the highest incidence in

Answer 25

cryptorchid the non-neoplastic testicle is usually atrophied

Question 26

What 6 things do you see with Sertoli cell tumor

Answer 26

1) Non-neoplastic testicle is usually atrophied 2) Feminization 3) Aspermatogenesis 4) Prostatic disease 5) Bone marrow hypoplasia 6) Linear preputial erythema or hyperpigmentation Metastatic disease is uncommon

Question 27

What might you see with hyperestrogenism due to cystic ovaries

Answer 27

1) Caudal thighs, ventrum, flank alopecia that may become truncal 2) Gynecomastia 3) Abnormal estrous cycles (prolonged or shortened)

Question 28

What causes iatrogenic hyperestrogenism

Answer 28

chronic contact with human topical hormone replacement (estrogen)

Question 29

What might resolve alopecia X in an intact male

Answer 29

castration

Question 30

What are some other names for Alopecia X

Answer 30

-Adrenal Sex Hormone imbalance -Maturity onset growth hormone responseive dermatosis -Estrogen, testosterone responsive dermatosis -Castration responsive dermatosis -Pseudo-Cushings disease

Question 31

What breeds are associated with Alopecia X

Answer 31

nordic breeds most common: pomeranian, chow chow, samoyed, keeshond, siberian husky, malamute, norweigan elkhound, finish spitz, american eskimo miniature poodle

Question 32

What kind of dogs are alopecia X common in

Answer 32

Intact males young dogs- 2.5 yrs at onset northern breeds, mini poodle

Question 33

Alopecia X causes

Answer 33

hair cycle arrest

Question 34

What is Telogen Effluvium

Answer 34

acute widespread alopecia from telogen defluxion severe illness/metabolic stress (fever, pregnancy, lactation, shock, drugs) cause hairs to go into telogen stage hair loss starting 3-4 weeks or more (1-3 months) after incident as new hairs regrowing

Question 35

What causes telogen effluvium

Answer 35

severe illness/metabolic stress (fever, pregnancy, lactation, shock, drugs) cause hairs to go into telogen stage hair loss starting 3-4 weeks or more (1-3 months) after incident as new hairs regrowing

Question 36

Post-Clipping alopecia

Answer 36

follicular arrest in dogs with history of clipping, surgically scrubbed +/- epidural no hair regrowth, unknown etiology rest of the coat/skin is normal regrowth in 6-24 months (usually <1 year) melatonin? thyroid hormone? try low level laser 2x weekly for 2 month

Question 37

canine flank alopecia is common in what species

Answer 37

Airedales, Boxers, Schnauzers, Bulldogs

Question 38

What is seen with canine flank alopecia

Answer 38

alopecia restricted to the flank of boxers, bulldogs, schnauzers, airedales hyperpigmentation may be seasonally cyclic may involve melatonin deficiency normal dogs- decreased photoperiod, increased melationin to stimulate winter pelage

Question 39

What may cause canine flank alopecia seen in boxers and schnauzers and bulldogs and airedales

Answer 39

may involve melatonin deficiency normal dogs- decreased photoperiod, increased melationin to stimulate winter pelage may be able to resolve with melatonin supplementation

Question 40

How do you treat the follicular dysplasia seen with canine flank alopecia

Answer 40

often responds to melatonin therapy 50-75% respond melatonin implant with 4-6 month release low level laser- twice weekly for 2 months

Question 41

blue, fawn color coat seen in doberman, great dane, whippet where alopecia is restricted to the dilute area of the coat Starts 6-12 months to 2-3 years

Answer 41

Color Dilution Alopecia (follicular dysplasia)

Question 42

When does color dilution alopecia typically present

Answer 42

younger dogs Starts 6-12 months to 2-3 years

Question 43

What do you see diagnostically with color dilution alopecia

Answer 43

hairs with macromelanosomes that weaken the hair shafts biopsies: pigment coloring around hair follicle

Question 44

What breeds do you see acquired pattern alopecia (pattern baldness) in

Answer 44

Dachshund, boston terrier, chihuahua, whippet

Question 45

Acquired Pattern Alopecia (pattern baldness)

Answer 45

Alopecia that develops as young dogs (1-3 years) occurs in dachshund, boston terrier, chihuahua, whippet may respond to melatonin therapy photobiomodulation? No need to treat (cosmetic)

Question 46

What breeds typically get caudal thigh alopecia

Answer 46

greyhounds