Thyrotoxicosis

Question 1

Define Thyrotoxicosis

Answer 1

• Excessive thyroid hormone from gland hyperfunction

Question 2

What are the causes of thyrotoxicosis

Answer 2

• Grave’s disease (most common)
• Toxic multinodular goitre
• Toxic adenoma
• Ectopic thyroid diseae
• de Quervain’s thyroiditis
• Exogenouse
  
  • Iodine excess (food contamination, contrast media)

Question 3

What are the universal features of Hyperthyroidism?

Answer 3

• Anxiety, irritability
• sweating, heat intolerance
• tachycardia
• weight loss
• fatigue
• loose stool
• sexual dysfunction

Question 4

What are the features of Grave’s diseas?

Answer 4

• Diffuse Goitre
• Thyroid eye disease
• Grave’s exopthalmos
• Peritibial myxedema

Question 5

What is the Px of Grave’s disease?

Answer 5

1. B cells produce Thyroid-stimulating immunoglobulins (IgG)
2. Bind to receptors on follicular cells
3. Stimulate thyroid hormone production

Question 6

What other diseases is Grave’s disease associated with

Answer 6

• vitiligo
• T1DM
• Addisons

Question 7

What are the features of toxic multinodular goiter?

Answer 7

• Goitre with firm nodules
• >50 yo
• Iodine deficient

Question 8

What are the features of de Quervain’s thyroiditis?

Answer 8

• viral infection
• fever
• neck pain
• tenderness
• dysphagia
• hyperthyroid phase followed by hypothyroid

Question 9

How would you mx de Quervain’s thyroiditis?

Answer 9

• Self-limiting
• NSAIDs
• beta blockers

Question 10

What is Thyroid storm?

Answer 10

• Thyrotoxic crisis

Question 11

What are the features of Thyroid storm?

Answer 11

• agitation
• confusion
• tachycaardia
• coma
• HF

Question 12

What causes thyroid storm

Answer 12

• recent thyroid surgery
• recent radioiodine
• infection
• MI
• trauma

Question 13

How would you Mx thyrotoxicosis?

Answer 13

• Pharmacology
  
  • Carbimazole (first line)
    
    • 20-40mg/day for 4 weeks
  • Prophylthiouracil (second line)
  • B-blockers
    
    • propranolol 40mg/6h
• Radioiodine
• Thyroidectomy

Question 14

What are the strict rule for Radioiodine?

Answer 14

• must not be pregnant, must not be allowed pregnancy within 6months
• avoid close contact c children and pregnant women for 3 weeks
• limit contact c anyone for several days

Question 15

What are the Cx for thyrotoxicosis

Answer 15

• Thyrotoxic cardiomyopathy - HF
• angina
• AF
• osteoporosis
• opthalmopathy
• gynaecomastia

Question 16

What are the features of thyroid eye disease

Answer 16

• Exophthalmos
• proptosis
• conjunctival oedema
• corneal ulceration
• papilloedema
• loss colour vision
• opthalmoplegia

Question 17

What is the Px of Exophthalmous?

Answer 17

1. Thyroid-stimulating antibodies activae T-cells in retro-orbital space
2. T-cells secrete TNFa and TNFg
3. Increase fibroblas secretion of GAGs
4. GAG increase muscle expansion and adipocyte count
5. Anterior bulging of eyes

Question 18

What Ix would you perform for thyrotoxicosis?

Answer 18

• Bloods
  
  • fT4 & T3: elevation
  • TSH: undetectable
  • TSHrAb: Grave’s
• Special test
  
  • technitium/iodine uptake isotope scan

Question 19

If subclinical hyperthyroidism is suspected, what will the bloods show?

Answer 19

• fT4 & T3 normal
• TSH suppressed

Question 20

How would you Mx subclinical thyrotoxicosis?

Answer 20

• confirmed suppresed TSH persisten (check in 2-4months)
• check for non-thyroidal cause
  
  • pituitary
  • hypothalamus
  • TSH-suppressing medication (thyroxine, steroids)
• If TSH <0.1: tx sx
• If no sx, recheck after 6months

Question 21

What is carbimazole associated c?

Answer 21

• Agranulocytosis
• monitor FBC