Cutaneous manifestations of endocrine disease

Question 1

What are the ddx for symmetrical alopecia?

Answer 1

o Severe folliculitis: 
   o Superficial bacterial pyoderma 
   o Demodicosis 
   o Dermatophytosis 
o Self‐trauma due to pruritus 
   o Ectoparasites 
   o Atopic dermatitis (food‐, or environmentally‐induced, or both) 
o Abnormalities of the hair follicle anatomy or the hair cycle 
   o Follicular dysplasias 
   o Endocrinopathies 
   o Alopecia X 
   o Recurrent flank alopecia 
   o Pattern alopecia

Question 2

What are the main follicular dysplasias?

Answer 2

o Breed‐specific conditions (Portuguese Water Dog, Curly Coated Retriever, etc)
o Colour dilution alopecia
o Black hair follicular dysplasia
o Follicular lipidosis

Question 3

What are the alopecias associated with hair cycle arrest?

Answer 3

o Endocrinopathies
o Alopecia X
o Recurrent flank alopecia
o Pattern alopecia

Question 4

Which breeds get colour dilution alopecia?

Answer 4

Doberman Pinscher, Dachshund, Great Dane, Whippet, Italian Greyhound, Yorkshire Terrier, many others

Question 5

Which patients get black hair follicular dysplasia?

Answer 5

American Cocker Spaniel, Cavalier King Charles Spaniel, Dachshund, Dalmatian, Gordon Setter, Jack Russell Terrier, Schnauzer, crossbreds, many others

Question 6

Which breed gets follicular lipidosis?

Answer 6

Rottweiler

Question 7

Which breeds get alopecia X?

Answer 7

Alaskan Malamute, Siberian Husky, Chow Chow, Pomeranian, Miniature Poodle

Question 8

Which patients get cyclical flank alopecia?

Answer 8

Boxer, Bullmastiff, English Bulldog, Airedale Terrier, Doberman, Italian Spinone, German Shorthaired Pointer, many others

Question 9

Which patients get pattern alopecia?

Answer 9

Chihuahua, Dachshund, Miniature Pinscher, Boston Terriers

Question 10

Which patients are predisposed to HAC

Answer 10

Dachshund, Miniature Poodle, Terriers

Question 11

Which patients are predisposed to hypothyroidism

Answer 11

Boxer, Chow Chow, Doberman, English Bulldog, Spaniels, many others

Question 12

What are the main hormones that have an influence on the skin?

Answer 12

o Thyroid hormones 
o Glucocorticoids 
o Oestrogens 
o Androgens 
o Growth hormone

Question 13

What are the dermatological signs of hypothyroidism?

60-80% cases

Answer 13

Bilaterally symmetrical truncal alopecia
Focal alopecia of the nose and tail
Dull, dry, brittle hair coat
Seborrheic dermatitis
Ceruminous otitis externa
2ary superficial pyoderma/Malassezia dermatitis
Hyperpigmentation and lichenification
Poor wound healing
Myxoedema (‘tragic facial expression’)

Question 14

What are the systemic signs of hypothyroidism

Answer 14

o Weight gain/obesity (without polyphagia) – 40%!
o Lethargy/mental dullness
o Weakness
o Cold intolerance/hypothermia
o Exercise intolerance
o Bradychardia
o Ocular disorders/Neurological disorders

Question 15

What are the biochem findings of hypothyroidism

Answer 15

o Non‐regenerative anemia
o ↑ cholesterol
o ↓ TT4 ↓ free T4 ↑TSH

Question 16

What are the dermatological signs of feline hyperthyroidism?

Answer 16

Coat changes
Calcinosis cutis (metastatic calcification due to hyperphosphatemia)
Increased claw growth

Question 17

What are the dermatologic signs of canine HAC?

Answer 17

Bilateral alopecia
Hyperpigmentation
Comedones
Calcinosis cutis
Thin and inelastic skin
Telangiectasia (threadlike red lines or patterns on the skin)
Adult onset demodecosis
2ary superficial pyoderma/Malassezia dermatitis

Question 18

What are the systemic signs of HAC

Answer 18

o PU/PD
o Polyphagia 
o Muscle wasting 
o Distended, pendulous abdomen 
o Hepatomegaly 
o Panting 
o Systemic hypertension 
o Ligament laxity 
o Reproductive disorders 
o Ocular disorders/Neurological disorders

Question 19

What are the typical laboratory findings of HAC

Answer 19

o Stress leukogram (N↑L↓M↑E) 
o Thrombocytosis, mild erythrocytosis 
o ↑ALKP 
o ↑ cholesterol, ↑triglycerides 
o Urine SG <1018‐1020, proteinuria 
o ACTH stim test, dexamethasone suppression test, UCCR, etc

Question 20

How do you treat HAC

Answer 20

o Trilostane is the licensed drug in the UK
o Resolution of PU/PD usually occurs within the first 4 weeks of treatment o Resolution of skin signs takes up to 3 months or longer
o Topical +/‐ systemic antiseptics/antimicrobials may be needed
o DMSO gel for calcinosis cutis
o Ionised calcium

Question 21

What are the clinical signs of feline HAC

Answer 21

o The most common clinical signs in cats with HAC are DM and dermatologic abnormalities
o PU/PD, pot‐belly appearance, polyphagia
o Thin skin
o Fragile skin
o Curling of the pinnae

Question 22

What causes canine hyperoestrogenism

Answer 22

1. Male feminization syndrome in intact males with testicular tumours
   o Sertoli cell tumours (more common), interstitial tumours or seminomas
   o US needed when lack of palpable testicular mass or presence of retained neoplastic abdominal testicle
   o Tumour metastasis are possible
   o Pendulous prepuce
   o Feminization in some dogs: gynecomastia and attractiveness to other male dogs
2. Intact females with cystic ovaries (more common) or ovarian neoplasia
   o Gynecomastia
   o Vulvar hypertrophy
   o Abnormal oestrus cycle
   o Serosanguinous vulvar discharge

Can also occur is dog comes into contact with oestrogen containing drugs for humans (e.g. creams for menopause)

Question 23

What are signs of hyperoestrogenism

Answer 23

Comedones
Linear preputial erythema
Symmetrical bilateral alopecia
Hyperpigmentation

Question 24

Outline canine hyperandrogenism

Answer 24

o Usually caused by interstitial testicular tumours
o Excessive sexual behaviour
o Aggression
o Prostatic abnormalities
o Dermatological signs:
o Caudal and perianal gland hyperplasia (may persist despite neutering)
o Patchy ano‐genital hyperpigmentation