Thyroid

Subacute Lymphocytic Thyroiditis

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Subacute Lymphocytic Thyroiditis, Silent Sporadic Thyroiditis, Painless Sporadic Thyroiditis, Silent Thyroiditis

  • Pathophysiology
  1. Autoimmune lymphocytic infiltration of Thyroid
  2. Results in Thyroid follicle destruction with release of preformed Thyroid Hormone
  • Epidemiology
  1. More common in women by 4 fold
  • Signs
  1. Painless Goiter (50%)
  2. Hyperthyroidism (up tp 20%)
    1. Duration: Typically <4 months
    2. Followed by Hypothyroidism and then euthyroid
  • Differential Diagnosis
  1. Drug-Induced Thyroiditis
    1. See Drug-Induced Thyroiditis
  2. Postpartum Thyroiditis
    1. Nearly identical, except limited to Postpartum Period
  3. Hashimoto's Thyroiditis
    1. Similar, except pathology (Fibrosis, Hurthle Cells)
  4. Grave's Disease
    1. Presents with pretibial edema, Proptosis
  5. Subacute Thyroiditis
    1. Painful Thyroiditis
  • Labs
  1. Thyroid Function Tests (T4 Free and TSH)
    1. Vary based on phase of illness
  2. Antibodies
    1. Antithyroid Peroxidase Antibody or TPO Antibody (positive in 50%)
    2. Thyroid Stimulating Immunoglobulins absent
      1. Contrast with Grave's Disease
  • Imaging
  1. Radioiodine Uptake (Thyroid uptake and scan)
    1. Low uptake in hyperthyroid phase (contrast with Grave's Disease)
  • Management
  1. Beta Blockers (e.g. Propranolol)
    1. Indicated for Hyperthyroidism symptoms
  2. Levothyroxine
    1. Indicated for symptomatic Hypothyroidism or persistent, chronic Hypothyroidism
  • Course
  1. Resolves within 12 months (up to 18 months) in 89% of cases
  2. Hypothyroidism persists chronically in 10-20% of cases
  3. Recurrence in 5-10% of cases
  • References
  1. Bindra (2006) Am Fam Physician 73(10):1769-76 [PubMed]
  2. Quintero (2021) Am Fam Physician 104(6): 609-17 [PubMed]
  3. Sweeney (2014) Am Fam Physician 90(6): 389-96 [PubMed]