What are the possible clinical presentations and case scenarios of thyroiditis?

Clinical Presentations of Thyroiditis: Case Scenarios

Thyroiditis presents in several distinct clinical patterns, ranging from the dramatic painful neck swelling of subacute thyroiditis to the silent, asymptomatic presentation of painless thyroiditis, with each type requiring recognition of specific clinical features for accurate diagnosis and appropriate management. 1

Subacute Thyroiditis (De Quervain's Thyroiditis)

Classic Presentation

The patient presents with moderate-to-severe thyroid pain radiating to the ears, jaw, or throat. The pain typically begins in one area and spreads across the gland over several weeks 1. On examination, the thyroid is firm and exquisitely tender to palpation 1.

Associated Features

• Constitutional symptoms: Malaise, low-grade fever, and fatigue
• Thyrotoxic symptoms: Palpitations, tremor, heat intolerance, weight loss
• Laboratory findings:
  • Suppressed TSH with elevated free T4 and T3
  • Markedly elevated ESR or CRP (key diagnostic feature)
  • Mild anemia is common
  • Low radioactive iodine uptake (RAIU)
• Ultrasound: Diffuse heterogeneity with decreased or normal color-flow Doppler 1

Atypical Presentations

Recent case reports highlight that subacute thyroiditis can present without neck pain, manifesting as:

• Persistent fever of unknown origin 2
• Weight loss and night sweats mimicking tuberculosis or lymphoma 3
• Thyroid cartilage thickening without typical anterior neck pain 3

Clinical Pitfall: In resource-limited settings or when neck pain is absent, subacute thyroiditis is frequently misdiagnosed as tuberculosis, requiring high clinical suspicion when thyrotoxic symptoms accompany unexplained fever 3, 2.

Painless (Silent) Thyroiditis

Typical Presentation

This patient appears with thyrotoxic symptoms but no thyroid pain or tenderness 1. The presentation is insidious and often discovered incidentally.

Key Clinical Contexts

Postpartum Thyroiditis (Most Common Scenario):

• Occurs in up to 10% of pregnancies in the United States
• Timing: 1-6 months postpartum
• Classic triphasic pattern (seen in only 25% of cases):
  1. Thyrotoxicosis (1-6 months postpartum)
  2. Hypothyroidism (follows thyrotoxic phase)
  3. Return to euthyroidism (9-12 months postpartum)
• More common patterns:
  • 43% present with hypothyroidism alone (no preceding thyrotoxicosis)
  • 32% present with thyrotoxicosis alone (no subsequent hypothyroidism) 1

Risk Factors for Postpartum Thyroiditis:

• Positive TPO antibodies in first trimester (27-fold increased risk)
• Tobacco smoking
• Bottle feeding (possibly due to higher maternal thyroid iodine exposure) 1

Non-Postpartum Painless Thyroiditis:

• Can occur in men and non-pregnant women
• Associated with drug therapy:
  • Lithium
  • Interferon-alpha (IFN-α)
  • Interleukin-2
  • Not associated with IFN-β therapy 1

Laboratory Features

• Suppressed TSH with elevated thyroid hormones
• Positive anti-TPO antibodies in majority of patients (key distinguishing feature)
• Low RAIU
• TRAb may be measurable but at lower titers than Graves' disease 1

Recent Diagnostic Challenge: Hashitoxicosis

A 2026 case series highlights a critical diagnostic pitfall: destructive thyrotoxicosis associated with Hashimoto's thyroiditis (hashitoxicosis) is frequently misdiagnosed as Graves' disease 4.

Key distinguishing features:

• Mean age 55.4 years (range 21-69)
• 40% have no overt hyperthyroid symptoms (only fatigue)
• Initially negative TRAb/TSI in 60% of cases
• Heterogeneous thyroid on ultrasound (75%)
• Low or normal RAI uptake
• Misdiagnosis occurred in 80% of cases, leading to inappropriate antithyroid drug use and accelerated hypothyroidism in 60% 4

Critical Clinical Point: The guideline-based recommendation is that TRAb testing is mandatory before initiating antithyroid drugs to distinguish destructive thyroiditis from Graves' disease 4.

Acute Suppurative Thyroiditis (Thyroid Abscess)

Presentation

Patients are typically euthyroid but present with acute bacterial infection symptoms 1:

• Fever (often high-grade)
• Painful, tender neck swelling
• Erythema and warmth over thyroid
• Dysphagia or odynophagia
• Potential airway compromise (medical emergency)

Rare Thyrotoxic Presentation

Occasionally presents with destructive thyrotoxicosis due to hormone release from inflamed tissue 1.

Etiology and Risk Factors

• Bacterial infection via:
  • Hematogenous spread
  • Direct extension through pyriform sinus fistula (present in 21% of pediatric cases)
• More common in children
• Accounts for <1% of thyroid diseases 5

Diagnostic Features

• Ultrasound shows abscess formation
• Elevated inflammatory markers
• Blood cultures may be positive
• Imaging to identify pyriform sinus fistula is essential to prevent recurrence 5

Atypical Presentation

Recent case series describe tuberculous thyroiditis presenting as:

• Bulky, heterogeneous thyroid gland on ultrasound
• Extensive necrosis on fine-needle aspiration
• Mimicking malignancy or other inflammatory conditions 6

Drug-Induced Thyroiditis

Amiodarone-Induced Thyrotoxicosis (AIT)

Presents in 5-10% of amiodarone-treated patients with either:

• Type 1: Iodine-induced hyperthyroidism (increased synthesis)
• Type 2: Destructive thyroiditis (hormone release)

Clinical features of destructive type:

• Thyrotoxic symptoms
• Low RAIU
• May require combined therapy with methimazole and corticosteroids
• Refractory cases require thyroidectomy (carries 9% mortality risk, but delay carries higher mortality) 1

Traumatic Thyroiditis

Follows direct trauma to the thyroid (surgery, biopsy, blunt trauma):

• Transient thyrotoxicosis from hormone release
• Usually self-limited
• Managed symptomatically with beta-blockers 1

Distinguishing Features Summary

When you see neck pain: Think subacute thyroiditis (but remember atypical painless presentations exist) 3, 2

When you see postpartum thyrotoxicosis: Distinguish from Graves' disease by:

• More pronounced goiter in Graves'
• Thyroid bruit or ophthalmopathy strongly suggests Graves'
• Higher TRAb titers in Graves'
• If nursing and testing needed: use 123I or technetium (not 131I) 1

When you see suppressed TSH with elevated thyroid hormones: Always check TRAb before starting antithyroid drugs to avoid misdiagnosing destructive thyroiditis as Graves' disease 4

When you see acute febrile illness with thyroid tenderness: Consider acute suppurative thyroiditis and evaluate for pyriform sinus fistula, especially in children 5

Critical Management Principles

Antithyroid drugs have NO role in destructive thyroiditis (painless, subacute, acute, traumatic) because hormone synthesis is already suppressed 1. Using them causes harm through unnecessary side effects and delays appropriate treatment.

Beta-blockers are the mainstay for symptomatic thyrotoxicosis in all forms of destructive thyroiditis 1.

Corticosteroids are indicated for:

• Moderate-to-severe subacute thyroiditis 1
• Severe painless thyroiditis (rarely needed) 1
• Amiodarone-induced thyrotoxicosis type 2 1

Hypothyroid phase management: Levothyroxine may be used during the hypothyroid phase but should be withdrawn after 3-6 months with thyroid function testing to verify recovery 1.