Thyroid overactivity, thyrotoxicosis
> common condition
> commonly affect women, age between 20 - 40 years old
> common hyperthyroidism conditions: Graves' disease. toxic multinoduular goitre, toxic adenoma, de
Quervain's thyroiditis, postpartum thyroiditis
> Clinical features -
Symptoms:
- weight loss - muscle weakness - itching
- increased appetite - stiffness - thirst
- irritability - malaise - vomiting
- restlessness - choreoathetosis - diarrhoea
- tremor - breathlessness - eye complaints
- heat intolerance - palpitation - goitre
- oligoamenorrhoea - loss of libido - gynaecomastia
- onycholysis - sweating - tall stature (in children)
Signs:
- tremor - psychosis
- hyperkinesia - systolic hypertension
- tachycardia or atrial fibrillation - cardiac failure
- full pulse - conjunctival oedema
- warm peripheries - ophthalmoplegia
- exophthalmos - periorbital oedema
- lid lag and 'stare' - weight loss
- goitre, carotid bruit - proximal myopathy
- onycholysis - palmar erythema
- Graves' dermopathy - Thyroid acropacity
- pretibial myxoedema
> Investigations:
- Serum TSH: low (< 0.05 mU/L)
- Elevated free T4 and t3 hormones
- Presence of microsomal and thyroglobulin antibodies in Graves' disease
- Ultrasound: differentiate Graves' disease from toxic adenoma
> Management
1) Antithyroid drugs
- carbimazole, methimazole
- block thyroid biosynthesis
- side effects: agranulocytosis
- if toxicity occurs, propylthiouracil
2) Beta blockers
- to provide rapid symptomatic control
3) Radioactive iodide
- Iodine - 131
- contraindicated in pregnancy and in breast-feeding mother
- accumulates in gland and results in irradiation and tissue damage
4) Surgery
- subtotal thyroidectomy indicated in patients that rendered euthyroid
- complications: bleeding, hypocalcemia, hypothyroidism, hypoparathyroidism, recurrent laryngeal nerve
palsy, recurrent hyperthyroidism
- indications: large goitre, drug side-effects, poor compliance, defaulted radioiodine, suspicion of
malignancy
