Clinical thyroid disease - second half

Question 1

Give a wee bit of epidemiology of hyperthyroidism

Answer 1

Fairly common - mainly affects women (5:1)

Nearly all caused by thyroid problems - rarely pituitary causes present

Question 2

What are the main types (causes) of hyperthyroidism?

Answer 2

Graves’ disease (70%)

Toxic multinodular goitre (20%)

Solitary toxic adenoma/nodule

Pituitary adenoma (secondary)

Question 3

What are the causes of thyrotoxicosis without hyperthyroidism?

Answer 3

Destructive thyroiditis:

• Post partum thyroiditis
• De Quervain’s thyroiditis
• Amiodarone induced

Excessive thyroxine administration

Question 4

What are the presenting signs/symptoms for hyperthyroidism?

Answer 4

Goitre ± bruit

Lid lag & ‘stare’ (eye signs)

Proximal muscle wasting

Weight loss

Tremor, Hyperkinesis, Tachycardia, Atrial Fibrillation

Question 5

What is Graves’ disease?

What differentiates it from other types of hyperthyroidism?

Answer 5

Most common cause of hyperthyroidism - autoimmune cause

It causes diffuse goitre ± bruit

Also causes Thyroid eye disease and is the only type to cause exophthalmos

Question 6

What is a common presenting complication of hyperthyroidism in the elderly?

Answer 6

Presentation with Atrial fibrillation

Question 7

What type of thyrotoxicosis are the elderly likely to get?

Answer 7

Multi-nodular goitre

Characteristic goitre & absence of Graves’ disease

Question 8

What are the investigations for hyperthyroidism?

Answer 8

Thyroid function tests:

• Serum TSH _{- will be suppressed in <strong>primary</strong> hyperthyroidism}
• FT₃ & FT_{4 - Raised T3/4 confirms diagnosis}
• TSH receptor stimulating antibodies _{- routine}

Question 9

What happens in Subacute (de Quervain’s) thyroiditis?

Describe how it would present?

Answer 9

Rare type of condition - often triggered by viruses - which causes Thyrotoxicosis for a few weeks before flipping to hypothyroidism for a few months

Patient is usually Younger (<50) & have history of painful goitre and fever/myalgia (from infection) and will have elevated ESR

Question 10

Give an overview of the management of hyperthyroidism/thyrotoxicosis

Answer 10

3 routes are available:

• Antithyroid drugs
• Radioiodine
• Surgery

Question 11

What is the main antithyroid drug used to treat hyperthyroidism?

How does it work?

What is the alternative option to it?

Answer 11

Carbimazole

inhibit the formation of thyroid hormone

also has a slight immunosuppressive action

Alternative is Propylthiouracil

Question 12

Describe the dosage regime for Carbimazole

Answer 12

Gradual dose titration

Starting at 20-40mg daily

Once euthyroid - maintain with 5mg daily

Question 13

What are the risks and side effects of antithyroid drugs such as Carbimazole?

Answer 13

Rash is fairly common

More important risks are:

Hypothyroidism

Agranulocytosis - (presents with fever/sore throat)

Question 14

What groups of people may require long-term, low-dose ATD’s?

Answer 14

Elderly

Cardiac complications

Unwilling to undergo Radioiodine therapy

Question 15

What are the indications and contraindications for Radioiodine therapy in a patient with hyperthyroidism?

Answer 15

• Indicated:*
• 2nd line to ATD’s if not working/tolerated
• Contraindicated:*
• Pregnancy & breastfeeding
• Severe eye disease

Question 16

What would results of a thyroid function test be for subclinical hyperthyroidism?

Answer 16

TSH suppressed

FT_3/4 normal

Question 17

What are the risks associated with subclinical hyperthyroidism?

When is treatment recommended?

Answer 17

Can cause:

• decreased bone density (post-menopausal)
• increased risk of Atrial fibrillation (esp in elderly)

Treatment considered with ATD/RAI if persistent - especially in elderly or those with increased cardiac risk