Thyroid Disease

Question 1

Sub-clinical hypothyroidism

What is it?

Causes

Answer 1

Sub-clinical hypothyroidism is generally defined as a mildly raised TSH (<10mU/L) and normal T3 and T4 levels

Causes:
- Viral Illness

Question 2

Sub-clinical hypothyroidism

Management

Answer 2

Management of these patients is a contentious issue but generally involves:

• Excluding other causes of a raised TSH such as inter-current illness.
• Rechecking thyroid function in 3-6 months.
• Most patients require no treatment.
• Thyroxine replacement is an option although there is little evidence to show benefit.

Question 3

What is subclinical hyperthyroidism?

Answer 3

Sub-clinical hypothyroidism is defined as low TSH in conjunction with normal T3 and T4. Patients may or may not be symptomatic.

Question 4

Management of subclinical hyperthyroidism

Answer 4

• Assessment for features of hyperthyroidism
• Exclude causes of transiently suppressed TSH such as medication (e.g. steroids, lithium, anti-Parkinson’s medications).
• Repeat thyroid function tests in 3-6 months.
• Endocrinology referral if persistent results.

Question 5

Grave’s Disease

Clinical Features

Answer 5

• Typical features of thyrotoxicosis
  specific signs limited to Grave’s (see below)

Features seen in Graves’ but not in other causes of thyrotoxicosis:

• eye signs (30% of patients): exophthalmos, ophthalmoplegia
• pretibial myxoedema
• thyroid acropachy

Question 6

Grave’s Disease

Antibodies

Answer 6

Autoantibodies
TSH receptor stimulating antibodies (90%)
anti-thyroid peroxidase antibodies (75%)

Question 7

Grave’s Disease / Hyperthyroidism

Management

Answer 7

Uncomplicated hyperthyroidism is treated as follows:
- Symptom relief: Propranolol

• Medical: Either ‘titration-block’ or ‘block and replace’ regimens
  1. Carbimazole – contraindicated in pregnancy
  2. Propylthiouracil – Treatment of choice in first trimester pregnancy/thyroid storm
  ​
  Radio-iodine
• Definitive management for multinodular goitre and adenomas
• Contraindicated in Graves eye disease because it may worsen symptoms [I of iodine, the eye looks at the i and says no, i’m the only i that matters]
  ​
  Thyroidectomy
• Indicated for recurrence, goitres that obstruct other structures, potential cancer.
• May lead to hypoparathyroidism and laryngeal nerve damage.
  ​

Question 8

Thyroid storm

What is it?

Causes

Answer 8

Thyroid storm is a rare but life-threatening complication of thyrotoxicosis. It is typically seen in patients with established thyrotoxicosis: too much thyroid hormones

thyroid or non-thyroidal surgery
trauma
infection
acute iodine load

Question 9

Thyroid storm

Clinical Features

Answer 9

fever > 38.5ºC
tachycardia
confusion and agitation
nausea and vomiting
hypertension
heart failure
abnormal liver function test - jaundice may be seen clinically

Question 10

Thyroid Storm

Management

Answer 10

Thyroid storm is treated as follows:
- IV propranolol
- IV digoxin
Propylthiouracil through NG tube followed by Lugol’s iodine 6 hours later
Prednisolone/hydrocortisone

Question 11

Hashimoto Thyroiditis

What is it?

Answer 11

Hashimoto’s thyroiditis (chronic autoimmune thyroiditis) is an autoimmune disorder of the thyroid gland.

It is typically associated with hypothyroidism although there may be a transient thyrotoxicosis in the acute phase.

Question 12

Hashimoto Thyroiditis

Clinical Features

Antibodies

Answer 12

features of hypothyroidism: weight gain, loss of lateral third of eyebrows
goitre: firm, non-tender

anti-thyroid peroxidase (most commonly) and also anti-Tg antibodies