Thyroid Disease Flashcards
1
Q
Causes of hyperthyroidism
A
- Primary hyperthyroidism (thyroid pathology causing excessive production)
- Grave’s disease where TRAb bind to TSH receptors and stimulate thyroid hormone production)
- Toxic multinodular goitre
- Solitary toxic adenoma/nodule
- de Quervain’s thyroiditis
- Postpartum thyroiditis
- Amiodarone-induced thyrotoxicosis
- Secondary hyperthyroidism (excessive TSH resulting in overstimulation)
2
Q
Presentation of hyperthyroidism
A
- Universal features
- Weight loss
- Increased appetite
- Irratibility/behavioural change/anxiety
- Tremor
- Sweating and heat intolerance
- Tachycardia or AF
- Full pulse
- Warm vasodilated capillaries
- Frequent loose stools
- Sexual dysfunction
- Grave’s Disease features
- Exopthalmos/proptosis (bulding of eye anteriorly)
- Lid lag and ‘stare’
- Diffuse goitre (without nodules)
- Pretibial myxoedema (deposits of mucin under the skin, waxy, oedematous appearance)
- Toxic multinodular goitre features
- Goitre with firm nodules
- Most patients are aged over 50
3
Q
Causes of hypothyroidism
A
- Primary hypothyroidism
- Hashimoto’s thyroiditis
- Atrophic (autoimmune hypothyroidism)
- Iodine deficiency
- Postpartum thyroiditis
- Dyshormonogenesis (rare genetic condition causing defects in synthesis of thyroid hormones)
- Secondary to treatment of hyperthyroidism
- Medications (i.e. lithium, amiodarone)
- Secondary hypothyroidism (disease of the pituitary)
- Tumours
- Infection
- Vascular (i.e. Sheehan Syndrome)
- Radiation
4
Q
Signs and symptoms of hypothyroidism
A
- Tiredness
- Weight gain
- Fluid retention (oedema, pleural effusions, ascites)
- Heavy or irregular periods
- Constipation
- Cold intolerance
- Goitre
- Mental slowness
- Hair loss
- Dry skin
- Bradycardia
- Slow-relaxing reflexes
5
Q
Investigation of thyroid disease
A
- TFTs
- Antithyroid peroxidase (anti-TPO) are present in most Grave’s Disease and Hashimoto’s Thyroiditis.
- Antithyroglobulin antibodies are usually present in Grave’s Disease, Hashimoto’s Thyroiditis and thyroid cancer.
- TSH Receptor Antibodies cause Grave’s Dieasese and so will be present.
- Thyroid US - useful for thyroid nodules
- Radioisotope scans are useful for hyperthyroidism and thyroid cancers
- Diffuse high uptake is found in Grave’s Disease
- Focal high uptake is found in toxic multinodular goitre and adenomas
- “Cold” areas (i.e. abnormally low uptake) can indicate thyroid cancer
6
Q
Thyroid function tests
A
- In hyperthyroidism, TSH is suppressed except in pituitary adenomas that secrete TSH.
- In hypothyroidism, TSH is high as it is trying to stimulate more thyroid hormone release except in secondary hypothyroidism where the TSH level will be low.
7
Q
Management of hyperthyroidism
A
- Antithyroid drugs
- Carbimazole (titration block or block and replace, 18 months to complete remission)
- Propulthiouracil
- BBs for symptomatic relief of adrenaline related symptoms
- Radioactive iodine
- Must not be pregnant or get pregnant within 6 months
- Must avoid close contact with children and pregnant women for 3 weeks
- Limit close contact with anyone for several days after receiving dose
- Thyroidectomy
- Require levothyroxine replacement for life
8
Q
Management of hypothyroidism
A
- Replacement therapy with levothyroxine (T4) is given for life
- Monitoring as the aim is to restore T4 and TSH levels to well within the normal range
9
Q
Definition of thyroid storm/thyrotoxic crisis
A
- Severe presentation of hyperthyroidism with:
- Pyrexia
- Tachycardia
- Delirium
10
Q
Presentation and investigaton of thyroid cancer
A
- Types
- Papillary
- Follicular
- Medullary
- Presentation
- Palpable thyroid nodule
- FHx of thyroid cancer
- Investigation
- TSH - normal
- FNA
- US neck
- Laryngoscopy
- Management
- Surgery +/- radiotherapy
- Radioactive iodine if recurrent or metastatic
- Chemotherapy is lymphoma
