Management of Thyroiditis

Initial Diagnostic Workup

The American College of Endocrinology recommends obtaining TSH and free T4 to confirm thyrotoxicosis, with low/normal TSH and elevated free T4, in patients with suspected thyroiditis 1, 2
T3 levels should be checked if patients are highly symptomatic with minimal FT4 elevation, as recommended by the American Thyroid Association 2
Thyroid peroxidase (TPO) antibodies should be tested to identify autoimmune etiology, according to the Endocrine Society 1, 3
TSH receptor antibody (TRAb) or thyroid stimulating immunoglobulin (TSI) should be tested to rule out Graves' disease if clinical features suggest it, as recommended by the American Association of Clinical Endocrinologists 1, 3, 4
A radioactive iodine uptake scan (RAIUS) or Technetium-99m scan should be performed if diagnosis is unclear, as it shows low uptake in thyroiditis versus high uptake in Graves' disease, according to the Society of Nuclear Medicine and Molecular Imaging 1

For Grade 1 (asymptomatic or mild symptoms) thyroiditis, the American College of Endocrinology recommends continuing cancer immunotherapy if applicable, and using beta-blockers for symptomatic relief of palpitations, tremors, and anxiety 1, 2
For Grade 1 thyroiditis, monitoring thyroid function every 2-3 weeks is recommended to catch the transition to hypothyroidism, as suggested by the Endocrine Society 1, 2
For Grade 2 (moderate symptoms) thyroiditis, the American Thyroid Association recommends considering holding immunotherapy until symptoms return to baseline, and using beta-blockers for symptomatic control 2
For Grade 3-4 (severe symptoms) thyroiditis, the American Association of Clinical Endocrinologists recommends holding immunotherapy until symptoms resolve, and using beta-blocker therapy, with consideration of hospitalization for severe cases 2

The American College of Endocrinology states that the thyrotoxic phase resolves within approximately 1 month, followed by hypothyroidism within 2 months of immunotherapy initiation in most patients, with a recommendation to initiate levothyroxine at approximately 1.6 mcg/kg/day for patients <70 years without cardiac disease 1, 5
The Endocrine Society recommends starting levothyroxine at 25-50 mcg in elderly patients or those with cardiac disease, titrating up gradually, and monitoring TSH every 6-8 weeks initially, then every 6-12 months once stable 5
Most patients require lifelong thyroid hormone replacement, as hypothyroidism is typically permanent, according to the American Thyroid Association 1, 3

The American Association of Clinical Endocrinologists recommends always starting corticosteroids before levothyroxine if both adrenal insufficiency and hypothyroidism are present, to avoid precipitating adrenal crisis 3
The Society of Nuclear Medicine and Molecular Imaging states that thyroiditis is self-limited, with low radioactive iodine uptake, typically painless, and transitions to hypothyroidism, whereas Graves' disease is persistent hyperthyroidism, with high radioactive iodine uptake, positive TRAb/TSI, and may have ophthalmopathy or thyroid bruit 1, 2
Physical exam findings of ophthalmopathy or thyroid bruit are diagnostic of Graves' disease and warrant early endocrine referral, according to the American Thyroid Association 2