Thyrotoxicosis Flashcards
What is Graves’ disease?
Graves’ disease is an autoimmune thyroid disease in which the body produces IgG antibodies to the thyroid-stimulating hormone (TSH) receptor.
What is the most common cause of thyrotoxicosis?
Graves’ disease is the most common cause of thyrotoxicosis.
In which age group is Graves’ disease typically seen?
Graves’ disease is typically seen in women aged 30-50 years.
What are the typical features of thyrotoxicosis?
Typical features of thyrotoxicosis include specific signs limited to Graves’ disease.
What are the eye signs associated with Graves’ disease?
Eye signs seen in Graves’ disease include exophthalmos and ophthalmoplegia.
These signs are present in 30% of patients.
What is pretibial myxoedema?
Pretibial myxoedema is a specific sign associated with Graves’ disease.
What is thyroid acropachy?
Thyroid acropachy is a triad of digital clubbing, soft tissue swelling of the hands and feet, and periosteal new bone formation.
What are the autoantibodies associated with Graves’ disease?
The autoantibodies associated with Graves’ disease include TSH receptor stimulating antibodies (90%) and anti-thyroid peroxidase antibodies (75%).
What does thyroid scintigraphy show in Graves’ disease?
Thyroid scintigraphy shows diffuse, homogenous, increased uptake of radioactive iodine.
Thyroid scintigraphy shows homogenous uptake consistent with Grave’s disease
What is the optimal management of Graves’ disease?
There is no clear guidance on the optimal management of Graves’ disease. Treatment options include anti-thyroid drugs (ATDs), radioiodine treatment, and surgery.
What is the most popular first-line therapy for Graves’ disease?
Anti-thyroid drugs (ATDs) have emerged as the most popular first-line therapy in recent years.
What factors support the use of anti-thyroid drugs?
Significant symptoms of thyrotoxicosis or patients with a significant risk of hyperthyroid complications, such as elderly patients or those with cardiovascular disease.
What is the initial treatment to control symptoms in Graves’ disease?
Propranolol is used to help block the adrenergic effects.
What does NICE recommend for patients with Graves’ disease?
NICE recommends that patients are referred to secondary care for ongoing treatment.
When should carbimazole be considered in primary care?
Carbimazole should be considered if patients’ symptoms are not controlled with propranolol.
What is the initial dosage and duration for carbimazole therapy?
Carbimazole is started at 40mg and reduced gradually to maintain euthyroidism, typically continued for 12-18 months.
What is a major complication of carbimazole therapy?
Agranulocytosis is a major complication of carbimazole therapy.
What is the ‘block-and-replace’ regime in ATD therapy?
Carbimazole is started at 40mg, and thyroxine is added when the patient is euthyroid. Treatment typically lasts for 6-9 months.
What is the advantage of ATD titration regime over block-and-replace?
Patients following an ATD titration regime have been shown to suffer fewer side effects than those on a block-and-replace regime.
When is radioiodine treatment used?
Radioiodine treatment is often used in patients who relapse following ATD therapy or are resistant to primary ATD treatment.
What are the contraindications for radioiodine treatment?
Contraindications include pregnancy (should be avoided for 4-6 months following treatment) and age < 16 years. Thyroid eye disease is a relative contraindication.
What is the expected outcome after radioiodine treatment?
The majority of patients will require thyroxine supplementation after 5 years, depending on the dose given.
What is subclinical hyperthyroidism?
Subclinical hyperthyroidism is defined as normal serum free thyroxine and triiodothyronine levels with a thyroid stimulating hormone (TSH) below normal range (usually < 0.1 mu/l).
What are the causes of subclinical hyperthyroidism?
Causes include multinodular goitre, particularly in elderly females, and excessive thyroxine which may give a similar biochemical picture.
Why is it important to recognize subclinical hyperthyroidism?
It is important due to its potential effects on the cardiovascular system (atrial fibrillation), bone metabolism (osteoporosis), quality of life, and increased likelihood of dementia.
How is subclinical hyperthyroidism managed?
Management involves monitoring TSH levels, which often revert to normal; intervention is warranted only if levels are persistently low.
What is a reasonable treatment option for subclinical hyperthyroidism?
A reasonable treatment option is a therapeutic trial of low-dose antithyroid agents for approximately 6 months in an effort to induce a remission.
Venn diagram showing how different causes of thyroid dysfunction may manifest. Note how many causes of hypothyroidism may have an initial thyrotoxic phase.
What are general features of thyrotoxicosis?
Weight loss, ‘Manic’ restlessness, heat intolerance
What cardiac symptoms are associated with thyrotoxicosis?
Palpitations, tachycardia
High-output cardiac failure may occur in elderly patients; a reversible cardiomyopathy can rarely develop.
What skin features are associated with thyrotoxicosis?
Increased sweating, pretibial myxoedema, thyroid acropachy
What is pretibial myxoedema?
Erythematous, oedematous lesions above the lateral malleoli
What is thyroid acropachy?
Clubbing of fingers
What gastrointestinal symptom is associated with thyrotoxicosis?
Diarrhoea
What gynaecological symptom is associated with thyrotoxicosis?
Oligomenorrhea
What neurological symptoms are associated with thyrotoxicosis?
Anxiety, tremor
Thyroid scintigraphy shows patch uptake with multiple foci consistent with toxic multinodular goitre
What does toxic multinodular goitre describe?
Toxic multinodular goitre describes a thyroid gland that contains a number of autonomously functioning thyroid nodules resulting in hyperthyroidism.
What does nuclear scintigraphy reveal in toxic multinodular goitre?
Nuclear scintigraphy reveals patchy uptake.
What is the treatment of choice for toxic multinodular goitre?
The treatment of choice is radioiodine therapy.
