II. Pathophysiology
- Autoimmune lymphocytic infiltration of Thyroid
- Results in Thyroid follicle destruction with release of preformed Thyroid Hormone
III. Epidemiology
- More common in women by 4 fold
IV. Signs
- Painless Goiter (50%)
-
Hyperthyroidism (up tp 20%)
- Duration: Typically <4 months
- Followed by Hypothyroidism and then euthyroid
V. Differential Diagnosis
- Drug-Induced Thyroiditis
-
Postpartum Thyroiditis
- Nearly identical, except limited to Postpartum Period
-
Hashimoto's Thyroiditis
- Similar, except pathology (Fibrosis, Hurthle Cells)
-
Grave's Disease
- Presents with pretibial edema, Proptosis
- Subacute Thyroiditis
VI. Labs
-
Thyroid Function Tests (T4 Free and TSH)
- Vary based on phase of illness
- Antibodies
- Antithyroid Peroxidase Antibody or TPO Antibody (positive in 50%)
- Thyroid Stimulating Immunoglobulins absent
- Contrast with Grave's Disease
VII. Imaging
-
Radioiodine Uptake (Thyroid uptake and scan)
- Low uptake in hyperthyroid phase (contrast with Grave's Disease)
VIII. Management
-
Beta Blockers (e.g. Propranolol)
- Indicated for Hyperthyroidism symptoms
-
Levothyroxine
- Indicated for symptomatic Hypothyroidism or persistent, chronic Hypothyroidism
IX. Course
- Resolves within 12 months (up to 18 months) in 89% of cases
- Hypothyroidism persists chronically in 10-20% of cases
- Recurrence in 5-10% of cases
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| Definition (NCI) | Thyroiditis associated with painless enlargement of the thyroid gland. It occurs more frequently in females and is characterized by alterations between hyperthyroidism and hypothyroidism and the eventual return to normal thyroid gland function. |
| Concepts | Disease or Syndrome (T047) |
| SnomedCT | 361126006, 18018005 |
| English | Silent Thyroiditis, Subacute Painless Thyroiditis, Subacute lymphocytic thyroiditis, Subacute lymphocytic thyroiditis (disorder), Subacute Lymphocytic Thyroiditis |
| Spanish | tiroiditis linfocítica subaguda (trastorno), tiroiditis linfocítica subaguda |
