Graves' Disease

Question 1

Definition

Answer 1

· The most common cause of hyperthyroidism. Caused by the presence of TSH-receptor stimulating antibodies that lead to hyperthyroidism due to loss of negative feedback.

Question 2

Aetiology

Answer 2

· Caused by the presence of TSH-receptor stimulating antibodies

· These antibodies are also responsible for the special features of Graves disease (exophthalmos, pretibial myxoedema)

Question 3

Risk factors

Answer 3

o Family history
o High iodine intake
o Smoking
o Trauma to the thyroid gland
o Toxic multinodular goitre
o HAART
o Childbirth

Question 4

Epidemiology

Answer 4

· Hyperthyroidism is COMMON

· Graves’ is the most common cause of hyperthyroidism (75%)

· Rarely occurs in children

Question 5

Presenting symptoms

Answer 5

· Weight loss despite increased appetite
· Irritability
· Weakness
· Diarrhoea
· Sweating
· Tremor
· Anxiety
· Heat intolerance
· Loss of libido
· Oligomenorrhoea/amenorrhoea

Question 6

Signs on physical examination

Answer 6

· Palmar erythema
· Sweaty and warm palms
· Fine tremor
· Tachycardia (may be AF)
· Hair thinning
· Urticaria/pruritus
· Brisk reflexes
· Goitre
· Proximal myopathy
· Lid lag
· Gynaecomastia

Question 7

Investigations

Answer 7

· TFTs - low TSH + high T3/T4

· Autoantibodies
o Anti-TPO antibodies (thyroid peroxidase) - found in 75% of Graves
o Anti-thyroglobulin antibodies
o TSH-receptor antibodies - very sensitive and specific for Graves

· Imaging
o Thyroid ultrasound
o Thyroid uptake scan

· Inflammatory Markers - CRP/ESR will be raised in subacute thyroiditis