Lecture: dermatology and endocrine dz Flashcards Preview

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Flashcards in Lecture: dermatology and endocrine dz Deck (28)
1

Dermatologic DDX

PAIN4ME

P

  • Parasitic
    • fleas
    • scabies
    • demodex
    • other

2

Dermatologic DDX

PAIN4ME

A

  • Allergic
    • environment
    • food
    • parasite
    • contact

3

Dermatologic DDX

PAIN4ME

I

  • Immune mediated/Idiopathic/Imadummy

4

Dermatologic DDX

PAIN4ME

N

  • Neoplastic

5

Dermatologic DDX

PAIN4ME

M

  • Microbial
    • bacteria
    • yeast
    • dermatophyte

6

Dermatologic DDX

PAIN4ME

E

  • Endocrine
    • endogenous

7

Hypothyroidism

Types

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

8

Constantly be on look-out for

SICK EUTHYROID SYNDROME

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

9

Production of thyroid hormone

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

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

*T3 is important for metabolism

10

Functions of thyroid hormones (6)

If low....

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

11

Metabolic signs of hypothyroidism

  • lethargy
  • Inactivity
  • Weight gain
  • Cold intolerance

12

Reproductive signs of hypothyroidism

  • persistent anestrus
  • testicular atrophy

13

Cardiovascular signs hypothyroid

  • bradycardia
  • cardiac arrhythmias

14

GI signs hypothyroid

  • Diarrhea
  • Constipation

15

Hematologic signs hypothyroid

  • Anemia
  • Hyperlipidemia

16

Neuromuscular signs hypothyroid

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

17

ocular signs hypothyroid

  • corneal lipid deposits
  • uveitis

18

Dermatologic CS hypothyroid

  • 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

19

Hypothyroid DX

CBC

Chem

Thyroid panel

  • 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

20

hyperadrenocorticism most common in 

Boston terriers

21

Most common type of cushings

pituitary cushings

22

Dermatologic signs of cushing's

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

23

Tests for cushings

  • 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

24

Cushing's in cats

  • diabetes mellitus
  • Skin fragility

25

Alopecia X

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

26

Dog walks in with alopecia looks endocrine dz'd

can rule out cushings if

  • No PU/PD
  • No think skin

*hypothyroidism has a better prognosis

 

27

Treatment

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

28

Sertoli cell tumor

Derm signs

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