Flashcards in PBL 3 - Hyperthyroidism Deck (20)
List some of the symptoms of hyperthyroidism. (10)
What are the symptoms specific to Grave's disease? (4)
1. Weight loss
2. Heat intolerance
b. Periorbital oedema
c. Lid retraction/lag
e. Nerve compression
3. Pretibial myxoedema
4. Finger clubbing
List the causes of hyperthyroidism. Consider:
a) Primary hyperthyroidism (4)
b) Secondary hyperthyroidism (7)
Toxic multinodular goitre
Ectopic thyroid tissue, e.g.
---Metastatic follicular cancer
Exogenous thyroid hormones
Subacute de Quervain's thyroiditis (post-viral)
Drug-induced (e.g. amiodarone)
Thyroid hormone resistance syndrome
Define Grave's disease.
Autoimmune hyperthyroidism caused by autoantibodies; features classic signs of hyperthyroidism as well as additional symptoms specific to Grave's disease
Describe the pathophysiology of Grave's disease. (3)
1. High levels of circulating thyroid hormones.
2. Effects of increased hormone levels:
a. Increased metabolism
b. Increased sympathetic nervous activity
3. Autoimmune antibodies:
a. TSH-receptor antibodies
---Stimulate normal TSH receptors to increase stimulation of the thyroid gland
Describe the investigations that can be done for hyperthyroidism. (3)
1. TSH levels
2. Serum free T4 levels
a. Free T4 index
b. Measure of T4 protein binding
c. Thyroxine binding globulin levels
3. Serum/total T3 levels
What is thyrotoxicosis?
What is thyroid crisis/thyroid storm?
A life-threatening condition due to a severe worsening of previously undiagnosed or inadequately treated thyrotoxicosis; often presents with fever, agitation, nausea, vomiting and abdominal pain
List the causes of thyroid storm. (8)
2. Diabetic ketoacidosis
3. Physical/emotional trauma
8. No obvious cause
List the clinical features of thyroid storm. (5)
1. Very high fever
2. Extreme cardiovascular effects
b. Congestive heart failure
3. Severe CNS effects
c. Psychotic episodes
4. Altered liver function
5. Biochemical features:
c. High WBC count
Describe the treatment of hyperthyroidism. (3)
b. Propylthiouracil (PTU)
2. Radioactive iodine
a. Uses 131iodine
What is the mechanism of action of thionamides?
1. Inhibit thyroid peroxidase
a. Therefore there is no hormone synthesis
2. Inhibit peripheral T4 to T3 conversion
a. Especially PTU - this causes a more rapid effect
What are the side effects of thionamides? (2)
1. Maculopapular pruritic rash
a. Presents with sore throat, fever
List the SWEATING mnemonic for symptoms of hyperthyroidism.
Intolerance to heat/Irregular menstruation/Irritability
List the THYROIDISM mnemonic for symptoms of hyperthyroidism.
Heart rate increased
Intolerance to heat
Muscle wasting/weight loss
Which thionamide is used preferentially in pregnancy?
(Methimazole may cause aplasia cutis in foetus)
What needs to be monitored when giving propylthiouracil?
Describe the clinical signs of hyperthyroidism. (9)
Arrhythmias, esp. AF
Warm, moist skin
Summarise treatment for hyperthyroidism. (4)
1. Beta blockers
3. Radioiodine (131I)
List 4 risk factors for Graves' disease.
Other autoimmune disease
Environmental exposure (e.g. iodine)
Immune modulating treatment (e.g. interferon, alemtuzemab)