Thyrotoxicosis Flashcards
What is thyrotoxicosis.
The clinical effect of excess thyroid hormone, usually from gland hyperfunction.
What are the symptoms of thyrotoxicosis. (16)
Diarrhoea. Weight loss (if very high, paradoxical weight gain in 10%). Over active. Sweats. Heat intolerance. Palpitations. Tremor. Irritability. Labile emotions. Oligomenorrhoea and infertility.
Rarely: Psychosis. Chorea. Panic. Itch. Alopecia. Urticaria.
What are the clinical signs of thyrotoxicosis. (8)
Fast pulse (AF, SVT, VT rare). Warm moist skin. Fine tremor. Palmar erythema. Thin hair. Lid lag. Lid retraction. There may be goitre, thyroid nodules or bruits depending on the cause.
What are the specific signs of graves’ disease. (4)
Exophthalmos.
Ophthalmoplegia.
Pretibial myxoedema.
Thyroid acropachy (extreme manifestation, with clubbing, painful finger and toe swelling and periosteal reaction in limb bones).
What do you see on the TFTs in a patient with thyrotoxicosis. (2)
Low TSH (suppressed). High T3 and T4.
What may be seen on the blood results of a patient with thyrotoxicosis. (5)
There may be a mild normocytic anaemia. Mild neutropenia (in Graves). Raised ESR. Raised calcium. Raised LFTs.
What other tests should you do in a patient with thyrotoxicosis. (4)
Check thyroid autoantibodies.
Isotope scan if the cause is unclear (to detect nodular disease or subacute thyroiditis).
If ophthalmopathy test visual fields and eye movements.
What are the causes of thyrotoxicosis. (6)
Graves' disease. Toxic multinodulat goitre. Toxic adenoma. Ectopic thyroid tissue. Exogenous. Other (Subacute de Quervain's thyroiditis, drugs, postpartum, TB).
What is the prevalence of graves.
0.5%.
What proportion of hyperthyroid cases are due to graves.
2/3rds.
What is the female:male ratio for graves.
9:1.
What is the typical age of onset of graves. (2)
40-60.
Younger if there is a maternal family history.
What is the cause of grave’s disease.
Circulating IgG autoantibodies binding to and activating G protein coupled thyrotropin receptors.
What is the aetiology of graves. (3)
Smooth thyroid enlargement.
Increased hormone production (raised T3).
React with orbital autoantigens.
What are some triggers for grave’s disease. (3)
Stress.
Infection.
Childbirth.
What are some associations of graves. (3)
Vitiligo.
T1DM.
Addison’s.