Lecture: dermatology and endocrine dz

Question 1

Dermatologic DDX

PAIN4ME

P

Answer 1

• Parasitic
  
  • fleas
  • scabies
  • demodex
  • other

Question 2

Dermatologic DDX

PAIN4ME

A

Answer 2

• Allergic
  
  • environment
  • food
  • parasite
  • contact

Question 3

Dermatologic DDX

PAIN4ME

I

Answer 3

• Immune mediated/Idiopathic/Imadummy

Question 4

Dermatologic DDX

PAIN4ME

N

Answer 4

• Neoplastic

Question 5

Dermatologic DDX

PAIN4ME

M

Answer 5

• Microbial
  
  • bacteria
  • yeast
  • dermatophyte

Question 6

Dermatologic DDX

PAIN4ME

E

Answer 6

• Endocrine
  
  • endogenous

Question 7

Hypothyroidism

Types

Answer 7

• overdiagnosed (many factors affect testing)
• Primary
  
  • idiopathic atrophy
  • Lymphocytic thyroiditis
  • Neoplasia
• Secondary (pituitary gland)
• Tertiary (hypothalamus)
• Sick euthyroid syndrome

Question 8

Constantly be on look-out for

SICK EUTHYROID SYNDROME

Answer 8

• common reason for false diagnosis
• Illness interferes with thyroid levels
• these animals are not truly hyperthyroid

Question 9

Production of thyroid hormone

Answer 9

• Hypothalamus => TRH => Pituitary => TSH => Thyroid => T₄

*T₄ is important for testing, but is converted to T₃

*T₃ is important for metabolism

Question 10

Functions of thyroid hormones (6)

If low….

Answer 10

1. Growth: Alopecia
2. Protein synthesis: Altered metabolism
3. Lipid metabolism: Elevated cholesterol
4. Carbohydrate metabolism: Alteration
5. Hematopoiesis: Anemia (mild)
6. Reproduction: Decreased

Question 11

Metabolic signs of hypothyroidism

Answer 11

• lethargy
• Inactivity
• Weight gain
• Cold intolerance

Question 12

Reproductive signs of hypothyroidism

Answer 12

• persistent anestrus
• testicular atrophy

Question 13

Cardiovascular signs hypothyroid

Answer 13

• bradycardia
• cardiac arrhythmias

Question 14

GI signs hypothyroid

Answer 14

• Diarrhea
• Constipation

Question 15

Hematologic signs hypothyroid

Answer 15

• Anemia
• Hyperlipidemia

Question 16

Neuromuscular signs hypothyroid

Answer 16

• seizures
• ataxia
• circling
• vestibular signs
• facial nerve paralysis

Question 17

ocular signs hypothyroid

Answer 17

• corneal lipid deposits
• uveitis

Question 18

Dermatologic CS hypothyroid

Answer 18

• Seborrhea: Dry or Greasy
  
  • skin and/or ears
  • May not be infected
• Recurrent infections
  
  • skin and/or ears
• Hyperpigmentation
• Dry, brittle hair coat
• Alopecia: Variable

Question 19

Hypothyroid DX

CBC

Chem

Thyroid panel

Answer 19

• CBC
  
  • normochromic, normocytic, non-regenerative anemia
• Chemistry (variable)
  
  • increased cholesterol and tryglycerides
• Thyroid panel
  
  • dec TT4, Free T4
  • TSH
    
    • inc in primary
    • dec in secondary and tertiary

*TT3 and FT3 are unreliable

Question 20

hyperadrenocorticism most common in

Answer 20

Boston terriers

Question 21

Most common type of cushings

Answer 21

pituitary cushings

Question 22

Dermatologic signs of cushing’s

Answer 22

• Comedones
  
  • much more likely in cushings than hypothyroid
• Recurrent infections
• Demodicosis
• Cutaneous atrophy
• Mange (Demodex)
• Hyperpigmentation
• cacinosis cutis

Question 23

Tests for cushings

Answer 23

• ACTH stimulation test
  
  • not as good
  • affected by steroid use
• Low dose dexamethasone suppression test
  
  • better test
• Serum ACTH concentrations
• High dose dexamethasone suppression test

Question 24

Cushing’s in cats

Answer 24

• diabetes mellitus
• Skin fragility

Question 25

Alopecia X

Answer 25

* AKA * Growth hormone responsive dermatitis * Adrenal sex hormone imbalance * Pseudocushings * castration responsive dermatosis

Question 26

Dog walks in with alopecia looks endocrine dz'd

Answer 26

can rule out cushings if * No PU/PD * No think skin \*hypothyroidism has a better prognosis

Question 27

Treatment

Answer 27

* may not be necessary * Melatonin (40%) * If dog is intact, castration is recommended * Drugs * Methyltestosterone * Ketoconazole * Lydodren: dangerous * Trilostane: dangerous

Question 28

Sertoli cell tumor Derm signs

Answer 28

* Bilateral, symmetrical alopecia * Hyperpigmentation * Seborrhea * Ceruminous otitis externa * Gynecomastia * Linear preputial dermatosis