Hyperthyroidism (Graves + De Quervains)

Question 1

Epidemiology

Answer 1

Young/middle age (20-40 years)
Women

Question 2

Risk factors

Answer 2

Smokers
Stress
HLA-DR3
Autoimmune diseases:
- Vitiligo (main)
- Type 1 diabetes
- Addisons disease

Question 3

Aetiology

Answer 3

GRAVES (MC)
Toxic multinodular goitre = benign adenoma = most patients above 50
Toxic adenoma
De Quervain’s thyroiditis
Ectopic TSH secretion e.g., - ovarian teratoma,
- pituitary adenoma,
- hypothalamic tumour
Drugs:
- Amiodarone
- Iodine
(Both Hyper/hypo Wolff Chartoff effect)
- Lithium

Question 4

Pathophysiology (GRAVES)

Answer 4

Serum IgG antibodies = TSH receptor stimulating autoantibodies (TSHR-Ab) = stimulate T3/T4 production
Excess secretion + hyperplasia of thyroid follicles = hyperthyroidism and diffuse goitre
Anti-TSH antibodies react with orbital antigens in fat + connective tissue = retro-orbital inflammation = thyroid eye disease

Question 5

Pathophysiology (De Quervain’s)

Answer 5

Upper resp infection which spreads to the thyroid gland + target thyroid cells causing them to present abnormal proteins on their MHC class 1 molecules
- Aggregation of immune cells (CD8, T cells, antigen presenting macrophages) form tiny nodules within thyroid gland + destroy thyroid cells - T3 + T4 spill out into blood = transient hyperthyroidism = pituitary gland decreases TSH production

Question 6

GRAVES TRIAD

Answer 6

Ophthalmopathy
Dermopathy (pretibial myxoedema)
Acropachy (characteristic rash)

Question 7

Signs

Answer 7

Goitre
Tachycardia
Exophthalmos (graves specific)
Pretibial myxoedema
Muscle wasting
Fine tremor

Question 8

Symptoms

Answer 8

Heat intolerance
Diarrhoea
Wt loss
Hyperphagia
Anxiety
Oligomenorrhoea

Question 9

THYROIDISM

Answer 9

Tremor/Tachycardia
Heart rate increase
Yawning
Restless
Oligomenorrhoea
Intolerance to heat
Diarhhoea
Irritability/ Insomnia
Sweating
Muscle Wasting

Question 10

De Quervain’s specific sign

Answer 10

Swollen red tender goitre post viral infection

Question 11

Diagnosis (GRAVES)

Answer 11

FIRST LINE = Thyroid function test =
- Low TSH, High T3/4 = Primary Hyperthyroidism
- High TSH, High T3/4 = Secondary Hyperthyroidism
- High TSH, normal T4 = subclinical HypOthyroid
- Low TSH, normal T3/4 = subclinical HypERthyroid
Thyroid TSH receptor autoantibodies (TRAb) = high
Anti-TPO = 80% of cases (BUT MUCH MORE IN HYPO)
Thyroid USS = differentiate between Grave and TMG
CT of head = pituitary adenoma

Question 12

Diagnosis De Quervain’s

Answer 12

FIRST LINE: TFTs: High T3/T4 with low TSH

Question 13

Treatment

Answer 13

FIRST LINE: CARBIMAZOLE
SECOND LINE: PROPOTHIOURACIL (CI = pregnancy) Prevents T3 -> T4 conversion - block and replace - levothyroxine given to prevent iatrogenic hypO thyroid
Beta blockers for rapid symptom release
DEFINITVE TREATMENT = Radioactive I13 (CI = pregnancy) - destroys excess thyroid
LAST RESORT = Surgery

Question 14

De Quervain’s specific treatment

Answer 14

FIRST LINE = supportive care - analgesia (aspirin),
if severe PREDNISOLONE

Question 15

Carbimazole Side Effects

Answer 15

Agranulocytosis = presents as SORE THROAT

Question 16

Complications

Answer 16

Thyroid Storm - rapid deterioration of thyrotoxicosis and INCREASED T4!!!
- systemic decompensation
- AF
- HTN
- Coma