Hyperthyroidism Flashcards
Aetiology of hyperthyroidism
Low TSH
Graves disease
Toxic multinodular goitre/Plummer’s
Toxic adenoma
Amiodarone
Choriocarcinoma (raised hCG)
Thyroiditis: Viral (De Quervain’s), post-partum
Raised TSH
TSH-secreting pituitary tumour
Risk factors for hyperthyroidism
Autoimmune diseases e.g. T1DM, vitiligo, ‘s
Family history of autoimmune diseases
Female sex
Smoking/tobacco use
High iodine intake
Lithium therapy
Biological agent and cytokine therapies
Radiation
Radioiodine therapy for benign nodular goitre
Stress
Symptoms of hyperthyroidism
Heat intolerance
Diarrhoea
Irritability or mood swings
Sweating
Palpitations
Weight loss (increased appetite)
Tremor
Hair loss
Muscle weakness
Menstrual irregularity
Sexual dysfunction
Goitre
Signs of hyperthyroidism
Obs
- Tachycardia
- Hypertension
Head and neck
- Exophthalmos/proptosis
- Ophthalmoplegia
- Diffuse goitre
General
- Tremor
- Pretibial myxoedema/dermopathy (oedematous swelling above the lateral malleoli)
- Acropathy - clubbing with soft tissue swelling
- Palmar erythema
Investigations for hyperthyroidism
TFTs: Raised T4/T3, suppressed TSH (unless secondary)
- T3/T4 ratio raised in graves
TSH receptor Abs (Graves)
Anti-thyroid peroxidase Abs (Graves)
US thyroid
Technetium uptake scan
CT head and neck
Management for hyperthyroidism
Lifestyle: stop smoking
Symptomatic relief: Propranolol |Eye drops | Topical steroids
Antithyroid drugs (Titration: start low, increase | Block and replace: cause hypothyroidism then replace with levothyroxine):
- Carbimazole 40mg then reduce
- PTU (for first trimester pregnancy, <6m attempt for conception, pancreatitis)
Radioactive iodine
Surgery
What are the indications for surgery for hyperthryoidism
Cosmetic
Large size
Eye disease
Local compression
Intention to become pregnant
Suspected cancer
Hyperparathyroidism
Refractory to medical therapy
Must be euthyroid beforehand - place on beta blocker and carbimazole (takes 4-6 weeks)
What are the side effects of carbimazole and radioiodine
Carbimazole
Agranulocytosis (must stop if fever >48h or sore throat)
Rash
Iodine = radioactive
Initially increases size of thyroid → airway compression, worsen Graves’ eye disease
Patients must be advised against prolonged contact with children (including their own) and pregnant women.
Avoid pregnancy for the next 6 months (F) or 4 months (M)
Complications of hyperthyroidism
Bone
AF
Congestive heart failure
Loss of vision
Elephantiasic dermopathy
Thyroid storm (severe hyperthyroidism) – if untreated → death
Prognosis for hyperthyroidism
Associated with increased mortality (from cardiovascular disease)
Good prognosis with management
What does technetium uptake thyroid scan show
Graves’ disease: Diffuse uptake
Toxic multinodular goitre: Multinodular gland with single hot nodule
Thyroid cancer: Diffuse uptake with single cold nodule
De Quervain’s thyroiditis: No uptake
