What is the next step in management for a patient with evidence of thyroiditis on imaging and subclinical hyperthyroidism (elevated thyroid hormones with normal Thyroid-Stimulating Hormone (TSH)) on laboratory results?

From the Guidelines

For a patient with imaging evidence of thyroiditis and subclinical hyperthyroidism on labs, the next step should be to continue monitoring thyroid function every 2-3 weeks after diagnosis to catch the transition to hypothyroidism, as this is the most common outcome for transient subacute thyroiditis, and consider a beta-blocker for symptomatic relief if necessary, as recommended by the ASCO guideline update 1.

Key Considerations

• The patient's symptoms and grading of thyrotoxicosis should guide management, with asymptomatic or mild symptoms (G1) allowing for continued ICPi therapy and close monitoring, while moderate to severe symptoms may require holding ICPi and endocrine consultation 1.
• TSH and FT4 should be used for case detection in symptomatic patients, with T3 helpful in highly symptomatic patients with minimal FT4 elevations, and consideration of TSH receptor antibody testing if Graves’ disease is suspected 1.
• The natural history of thyroiditis often involves a hyperthyroid phase followed by euthyroidism or temporary hypothyroidism before resolution, so sequential monitoring is essential to guide management.

Management Approach

• For asymptomatic patients, close monitoring of thyroid function every 2-3 weeks is recommended, with treatment of transition to elevated TSH and low FT4 as for primary hypothyroidism 1.
• For symptomatic patients, beta-blockers such as atenolol or propranolol can be used for symptomatic relief, with consideration of endocrine consultation for additional workup and possible medical thyroid suppression for persistent thyrotoxicosis 1.
• Patients should be educated about the typical course of thyroiditis and advised to report worsening symptoms promptly, with consideration of hospitalization in severe cases requiring inpatient endocrine consultation and possible additional medical therapies 1.

From the Research

Next Steps for Subclinical Hyperthyroidism

• Evaluate the patient's symptoms and medical history to determine the best course of action
• Consider repeating thyroid function tests (TFTs) to confirm the diagnosis of subclinical hyperthyroidism, as the initial results may be influenced by various factors 2
• Assess the patient's risk factors for thyroid disease and consider ordering additional tests, such as thyroid antibodies or ultrasound, to evaluate the evidence of thyroiditis on imaging
• Monitor the patient's TFTs at regular intervals, taking into account the findings of the study that median TFT re-testing interval was lower than recommended for those with normal TFTs 2
• Consider consulting with an endocrinologist to determine the best treatment plan for the patient, as the study highlights the need for a new approach to ensuring optimum monitoring frequency 2

Considerations for Thyroid Function Test (TFT) Monitoring

• The study found that the majority of TFT requests are made outside recommended intervals, with a median re-test interval of 19.1 weeks 2
• The re-test interval was much lower than recommended for those with normal TFTs, and much longer than recommended for those with elevated TSH and low free thyroxine (fT4) or low TSH and high fT4 2
• These findings suggest that a more tailored approach to TFT monitoring may be necessary, taking into account the individual patient's needs and test results 2