Viral Thyroiditis Flashcards
Define viral thyroiditis.
Viral thyroiditis is a self-limited inflammation of the thyroid gland. It is associated with a triphasic clinical course that lasts for a few weeks to many months, characterised by transient thyrotoxicosis, hypothyroidism, and then a return to normal thyroid function in >90% of patients.
Explain the aetiology/risk factors of viral thyroiditis.
Viral infection
Summarise the epidemiology of viral thyroiditis.
There does not seem to be any global difference in epidemiology. The overall age- and sex-adjusted annual incidence rate calculated for one state in the US was estimated to be 4.9 cases per 100,000.
Recognise the presenting symptoms of viral thyroiditis. Recognise the signs of viral thyroiditis on physical examination.
Neck pain
Tender, firm, enlarged thyroid
Fever
Palpitations
Recent viral infection
Myalgia
Malaise
Tremor
Heat intolerance
Identify appropriate investigations for viral thyroiditis and interpret the results.
Thyroid-stimulating hormone (TSH)
Total T4, total T3, T3 resin uptake, free thyroxine index
T3:T4 ratio
Radioactive iodine uptake
ESR
CRP
Antithyroid antibodies (thyroid peroxidase antibodies)
Generate a management plan for viral thyroiditis.
- *Thyroid pain and tenderness:** Analgesic or corticosteroid
- *Tachycardia or anxiety or tremor:** Beta-blocker or calcium-channel blocker
- *Severe thyrotoxicosis:** Potassium iodide plus prednisolone
Identify the possible complications of viral thyroiditis and its management.
Thyroid storm
Long-term hypothyroidism
Summarise the prognosis for patients with viral thyroiditis.
In ≥90% of patients, there is a complete and spontaneous recovery and a return to normal thyroid function. However, the thyroid gland may exhibit irregular scarring between islands of residual functioning parenchyma. Up to 10% of patients may require permanent replacement with levothyroxine due to persistent hypothyroidism.
