Thyroid Disease

Question 1

What is the lifetime risk of thyroid disease in a woman?

Answer 1

20%

Question 2

When is undiagnosed thyroid disease especially dangerous?

Answer 2

Pregnancy/peripartam

Cardiac disease

Question 3

How often do ranges for thyroid function tests change during pregnancy?

Answer 3

Trimester to trimester

Question 4

What blood test is a good screening test for hypothyroidism?

Answer 4

TSH

Question 5

What blood tests do you do if you’re considering secondary hypothyroidism?

Answer 5

TSH and T4

Question 6

What is sub-clinical hypothyroidism?

Answer 6

T4 normal, elevated TSH

Question 7

What are the symptoms of hypothyroidism?

Answer 7

Malaise
Tiredness
Myalgia
Depression
Cold intolerance
Constipation
Weight gain

Question 8

What are the signs of hypothyroidism?

Answer 8

Delayed tendon reflexes
Bradycardia
Myxoedema
Voice change
Myopathy
Hypothermia
Effusions

Question 9

What are the most common causes of hypothyroidism?

Answer 9

Autoimmune
Iatrogenic
Drugs

Question 10

What is thyroiditis?

Answer 10

Inflammation of thyroid gland

Question 11

What is the natural history of thyroiditis?

Answer 11

Initially hyperthyroid phase because some follicles rupture and release thyroid hormone
- 4-8 weeks
Then have hypothyroid phase
- 4-8 weeks
Transient and self-limiting

Question 12

How is hypothyroidism diagnosed?

Answer 12

Check TSH and free T4
Correlate with symptoms and clinical exam
Anti-thyroid Abs can sometimes be helpful

Question 13

What is the treatment for hypothyroidism?

Answer 13

Thyroxine

- 1.3-1.6 mg/kg

Question 14

After how long do you adjust thyroxine dose?

Answer 14

6-8 weeks

- No hurry except in pregnancy

Question 15

What medications may decrease thyroxine absorption?

Answer 15

Iron tablets
Calcium tablets
Antacids
Cholestyramine

Question 16

Is a nuclear scan important in hypothyroidism?

Answer 16

No

Question 17

What are differential diagnoses for thyrotoxicosis?

Answer 17

Caffeine
Anxiety/panic disorder
Primary pulmonary/cardiac disorder

Question 18

What are the symptoms of hyperthyroidism?

Answer 18

Heat intolerance
Weight loss
Increased appetite
Increased sweating
Tremulousness
Anxiety
Emotional lability
Hair loss
Increased frequency of bowel movements
Menstrual irregularity

Question 19

What are some of the causes of hyperthyroidism?

Answer 19

Graves' disease
Toxic nodular goitre
Iodine-induced
- Radiographic
- Naturopathic remedies
- Amiodarone
Exogenous
Transient

Question 20

What are the possible signs of hyperthyroidism?

Answer 20

Increased heart rate
Irregularly irregular rhythm
Tremor
Skin, nail and hair changes
Thyroid size, consistency, bruit
- May have diffuse, soft goitre
- May have bruit over thyroid
Pemberton's sign

Question 21

What eye signs may be present in Graves’ disease?

Answer 21

Redness and irritation
Staring appearance
Mild double vision on extreme lateral gaze

Question 22

What are the investigations for hyperthyroidism?

Answer 22

TSH
Free T3 and T4
Nuclear scan if unsure of cause
Abs against TSH receptor if suspect Graves’ disease

Question 23

What is the appearance of a nuclear scan in Graves’ disease?

Answer 23

Normal/increased uniform uptake

Question 24

What is the appearance of a nuclear scan in thyroiditis?

Answer 24

Decreased/no uptake

- Due to inflammation

Question 25

What is the appearance of a nuclear scan if one or more nodules are present?

Answer 25

Non-uniform uptake

Question 26

Which age group is particularly at risk of developing atrial fibrillation as a result of hyperthyroidism?

Answer 26

Elderly

Question 27

What are the treatment options for hyperthyroidism?

Answer 27

``` Anti-thyroid drugs - Carbimazole - Propylthiouracil Radioactive iodine Surgery only if other reasons - Adverse reactions to drugs - Cosmetic/patient preference - Risk of malignancy ```

Question 28

What is the pattern of disease in Graves' disease?

Answer 28

Remitting-relapse

Question 29

What is the management of Graves' disease?

Answer 29

Try anti-thyroid drugs, but they don't often work | Need to remove thyroid, either via radiation/surgery

Question 30

Are anti-thyroid drugs safe to use in pregnancy and lactation?

Answer 30

Yes, but try and avoid use | - Propylthiouracil safer in first trimester

Question 31

What are the side effects of anti-thyroid drugs?

Answer 31

Commonly, rash | Very small risk of granulocytosis

Question 32

How long do you treat Graves' disease for with anti-thyroid drugs?

Answer 32

12-18 months

Question 33

What medication can be used to help alleviate the symptoms of hyperthyroidism initially?

Answer 33

Beta-blockers

Question 34

What are the features of radioactive iodine as a treatment for hyperthyroidism?

Answer 34

Very effective and permanent Permanent hypothyroidism frequent outcome Small risk of thyroid eye disease Must not be pregnant Must not have had ordinary iodine for months

Question 35

What are the features of surgery for thyrotoxicosis?

Answer 35

Usually only considered if - Large goitre with obstructive/cosmetic concerns - Significant possibility of incidental thyroid malignancy - Intolerant of anti-thyroid drugs and radioactive iodine therapy refused/contraindicated

Question 36

What tests may be helpful in the confirmation of thyroiditis?

Answer 36

CRP ESR WCC

Question 37

If antibody testing is negative in the instance of hyperthyroidism, what test can be done, and what can it indicate?

Answer 37

Measure thyroglobulin levels Elevated in thyroiditis If normal, may indicate exogenous cause

Question 38

What is the management of sub-clinical hypothyroidism?

Answer 38

Observe/treat according to clinical circumstances