This is the commonest cause of hyperthyroidism and is due to autoimmune process in which serum IgG antibodies bind to the thyroid TSH receptors and produce stimulation of thyroid hormone production, behaving like TSH.
Increased size and secretion of thyroid gland
GIT features include weight loss despite normal or increased appetite
Increased pulse pressure
Dyspnea on exertion
Tremor of hand
Finger clubbing periorbital myxedema
Loss of visual acuity
- Antithyroid drugs
- Subtotal thyroidectomy
- Radioactive iodine
An active derivative metabolite of carbimazole and propylthiouracil .these drugs act by reducing the synthesis thyroid hormone by inhibiting the iodinization of thyroxin.
Dose: 30-40 mg of methimazole or 300-400 mg of PTU are given until patient is euthyroid.
Improvement occurs in few weeks to months and then lower the dose that maintain euthyroidism and drug should be continued for 12-18 months.
Skin rash, agranlocytosis
Operation in a thyrotoxic patient risk the thyroid storm so first treat the patient with antithyroid drugs to return them to euthyroid state before surgery.
Increase success rate
Rapid cure of hyperthyroid state
Surgical and anesthesia side effects
Recurrent laryngeal nerve paralysis
A singe dose of iodine 131 I cause a decrease function and size of thyroid gland in 6-12 weeks.
Approx 75 % of patients are made euthyroid by a single dose. Eventually, almost all patients cured in this way.
Multiple doses may be needed