What are the typical symptoms and treatment options for a patient presenting with thyroiditis?

Thyroiditis Presentation and Management

Clinical Presentation Patterns

Thyroiditis typically presents with a triphasic pattern of thyroid dysfunction: initial thyrotoxicosis from release of preformed hormone, followed by hypothyroidism as stores deplete, then eventual restoration of normal function (though some develop permanent hypothyroidism). 1, 2

Subacute Thyroiditis (Most Common Symptomatic Form)

Presentation:

• Anterior neck pain radiating to jaw and ear 2, 3
• Fever (though may be absent in atypical presentations) 4, 2
• Thyroid tenderness and thyromegaly on palpation 4, 3
• Fatigue, myalgias, and symptoms of thyrotoxicosis (palpitations, heat intolerance, tremors, anxiety) 5, 1
• Often follows upper respiratory viral illness 2
• May present atypically as a painful thyroid nodule mimicking malignancy 3

Diagnostic Features:

• Suppressed TSH with elevated free T4 or T3 during thyrotoxic phase 5, 2
• Elevated inflammatory markers 3
• Low radioactive iodine uptake on thyroid scanning (distinguishes from Graves' disease) 5, 2
• Ultrasound shows heterogeneous, hypoechoic, ill-defined areas with low vascularization 3

Hashimoto Thyroiditis (Most Common Overall)

Presentation:

• Painless goiter 1, 2
• Symptoms of hypothyroidism: fatigue, weight gain, cold intolerance, constipation, depression 5, 1
• Often asymptomatic initially 1

Diagnostic Features:

• Elevated thyroid peroxidase (TPO) antibodies 5, 1, 2
• Elevated TSH with low free T4 in overt hypothyroidism 1, 2
• May present with subclinical hypothyroidism (elevated TSH, normal free T4) 1

Postpartum Thyroiditis

Presentation:

• Occurs within one year of delivery, miscarriage, or medical abortion 5, 1, 2
• Initial hyperthyroid phase (1-4 months postpartum) with palpitations, anxiety, weight loss 1, 2
• Followed by hypothyroid phase (4-8 months postpartum) with fatigue, depression, weight gain 1, 2
• Painless thyroid enlargement may occur 5, 1

Diagnostic Features:

• Abnormal TSH and/or free T4 levels 5
• Elevated anti-thyroid peroxidase antibodies support diagnosis 5, 1
• Low radioactive iodine uptake during hyperthyroid phase 2

Drug-Induced Thyroiditis

Presentation:

• Painless thyroiditis most commonly with anti-PD1/PD-L1 immunotherapy (6-20% incidence) 5
• May present with hyperthyroid symptoms or be asymptomatic and detected on routine monitoring 5
• Other causative drugs: amiodarone, interferon-alfa, interleukin-2, lithium, tyrosine kinase inhibitors 1, 6

Diagnostic Features:

• Thyrotoxicosis occurs average one month after starting immunotherapy 5
• Low/normal TSH with elevated free T4 or T3 5
• Negative TSH receptor antibodies (TRAb) or thyroid stimulating immunoglobulin (TSI) distinguishes from Graves' disease 5

Treatment Algorithms

Subacute Thyroiditis Treatment

Thyrotoxic Phase (Initial 1-2 months):

• Beta blockers (propranolol or atenolol) for symptomatic relief of palpitations, tachycardia, tremors, and anxiety 7, 1, 2
• NSAIDs (ibuprofen 600mg) for mild-to-moderate thyroid pain 4, 1, 2
• Prednisone 40mg daily for severe pain unresponsive to NSAIDs 4, 2
• Antithyroid drugs (methimazole, propylthiouracil) are NOT indicated as this is destructive thyroiditis, not increased hormone production 5, 7

Hypothyroid Phase (Months 2-4):

• Monitor TSH and free T4 every 4-6 weeks 1, 2
• Levothyroxine therapy only if TSH >10 mIU/L or symptomatic with TSH 4.5-10 mIU/L 8, 1
• Most cases are self-limited and do not require treatment 1, 2

Recovery Phase:

• Continue monitoring thyroid function every 3-6 months for first year 1, 2
• 5-15% develop permanent hypothyroidism requiring lifelong levothyroxine 1, 2

Hashimoto Thyroiditis Treatment

Overt Hypothyroidism (Low Free T4, Elevated TSH):

• Levothyroxine is mandatory regardless of symptoms 8, 1, 2
• Starting dose: 1.6 mcg/kg/day for patients <70 years without cardiac disease 8
• Starting dose: 25-50 mcg/day for patients >70 years or with cardiac disease 8
• Critical: In patients with suspected concurrent adrenal insufficiency, start corticosteroids before levothyroxine to prevent adrenal crisis 5, 8

Subclinical Hypothyroidism (Normal Free T4, Elevated TSH):

• Treat with levothyroxine if TSH >10 mIU/L regardless of symptoms 8
• Consider treatment if TSH 4.5-10 mIU/L with positive TPO antibodies (4.3% annual progression risk vs 2.6% without antibodies) 8, 1
• Monitor TSH every 6-8 weeks during dose titration, then every 6-12 months once stable 8

Postpartum Thyroiditis Treatment

Hyperthyroid Phase:

• Beta blockers for symptomatic relief (propranolol preferred) 5, 1, 2
• Antithyroid drugs are NOT indicated 1, 2
• Monitor TSH and free T4 every 4-6 weeks 5, 1

Hypothyroid Phase:

• Levothyroxine if TSH >10 mIU/L or TSH 4-10 mIU/L with symptoms or desire for fertility 5, 2
• Starting dose: 50-75 mcg daily 2
• Recheck thyroid function at 6 and 12 months postpartum to assess for permanent hypothyroidism 5, 1

Drug-Induced Thyroiditis (Immunotherapy-Related)

Thyrotoxic Phase:

• Conservative management is sufficient—this is self-limiting 5
• Beta blockers for symptomatic relief 5, 1
• Continue immunotherapy in most cases (high-dose corticosteroids rarely required) 5
• Monitor TSH every 4-6 weeks for first 3 months, then every second cycle 5, 8

Hypothyroid Phase (Occurs ~1 month after thyrotoxic phase, ~2 months from immunotherapy initiation):

• Start levothyroxine as this typically leads to permanent hypothyroidism 5
• Consider treatment even for subclinical hypothyroidism if fatigue or other symptoms present 5, 8
• Continue immunotherapy without interruption 5

Critical Diagnostic Pitfalls to Avoid

Do not diagnose thyroiditis based on single abnormal TSH value—30-60% normalize spontaneously on repeat testing 8, 1

Always obtain radioactive iodine uptake scan or thyroid ultrasound when diagnosis is uncertain—low uptake confirms destructive thyroiditis versus high uptake in Graves' disease 5, 7, 2

Check TSH receptor antibodies (TRAb) or thyroid stimulating immunoglobulin (TSI) to distinguish Graves' disease from thyroiditis when thyrotoxic 5

Never start levothyroxine before ruling out adrenal insufficiency in patients with suspected hypophysitis or central hypothyroidism—this can precipitate life-threatening adrenal crisis 5, 8

Recognize that subacute thyroiditis may present atypically as a painful thyroid nodule mimicking malignancy—ultrasound features of heterogeneous, hypoechoic, ill-defined areas with low vascularization suggest thyroiditis rather than neoplasm 3

Monitor for permanent hypothyroidism in all forms of thyroiditis—highest risk with Hashimoto (lifelong), postpartum (20-30% at one year), and immunotherapy-induced (most cases) 5, 1, 2