II. Definitions

  1. Thyroiditis
    1. Thyroid Gland Inflammation with or without Thyroid dysfunction

III. Labs

  1. Precautions
    1. Serum TSH may be falsely increased or decreased by medications and non-Thyroid conditions (See Serum TSH)
    2. Fluctuating Thyroid function (initial Hyperthyroidism followed by Hypothyroidism) is typical of some Thyroiditis (see below)
  2. Initial
    1. Thyroid Stimulating Hormone (TSH)
  3. Confirmatory
    1. Free Thyroxine (Free T4)
    2. Free Triiodothyronine (Free T3)
  4. Specific tests (as indicated)
    1. Thyroid peroxidase Antibody (TPO Antibody)
      1. Increased in Hashimoto's Thyroiditis, Postpartum Thyroiditis, Silent Thyroiditis and Subacute Thyroiditis

IV. Imaging

VI. Causes: Painful Thyroiditis

  1. Subacute Granulomatous Thyroiditis or Giant Cell Thyroiditis (uncommon)
    1. Postviral Thyroiditis with increased Thyroid peroxidase Antibody (TPO Antibody) and low RAIU (Radioactive Iodine uptake)
    2. Resolves to euthyroid state within 85% of cases (others may continue with Hypothyroidism)
  2. Suppurative Thyroiditis or Infectious Thyroiditis (rare)
    1. Presents with Thyroid pain and tenderness, high fever, Leukocytosis and cervical adenopathy
    2. Most common infectious causes are Streptococcus Pyogenes, Streptococcus Pneumoniae and Staphylococcus Aureus
  3. Radiation-Induced Thyroiditis (1% of I131 patients)
    1. Presents with transient Hyperthyroidism
  4. Traumatic Thyroiditis (rare)
    1. Self-limited Thyroiditis due to local Trauma
  5. Thyroid Hemorrhage
    1. Sudden solid Thyroid Nodule bleeding or infarction results in adjacent hemorrhagic cysts
    2. Even small hemorrhagic Thyroid cysts may cause pain, and in rare cases can cause local compression symptoms (Stridor, Dysphagia)

VII. Causes: Painless Thyroiditis

  1. Hashimoto's Thyroiditis (5-10% of cases)
    1. Chronic Autoimmune Thyroiditis (or Chronic Lymphocytic Thyroiditis)
    2. Presents as Hypothyroidism (most cases) with a non-tender Goiter
    3. Thyroid peroxidase Antibody (TPO Antibody) increased
  2. Postpartum Thyroiditis (5% of cases)
    1. Hyperthyroidism or Hypothyroidism or initial Hyperthyroidism followed by Hypothyroidism
    2. Thyroid peroxidase Antibody (TPO Antibody) increased and low RAIU (Radioactive Iodine uptake)
  3. Drug-Induced Thyroiditis (10% of cases)
    1. Causes: Amiodarone, Denileukin, Interferon alfa, Interleukin-2, Kinase Inhibitors and Lithium
  4. Subacute Lymphocytic Thyroiditis or Silent Thyroiditis (uncommon)
    1. Autoimmune Thyroiditis with increased Thyroid peroxidase Antibody (TPO Antibody) and low RAIU (Radioactive Iodine uptake)
    2. Resolves to euthyroid state within 85% of cases (others may continue with Hypothyroidism) and rare recurrence
  5. Riedel's Thyroiditis or Fibrous Thyroiditis (uncommon)
    1. Firm Goiter which may be associated with local compression (Stridor, Dysphagia)
    2. Destructive Thyroiditis that may be associated with Hypocalcemia if the Parathyroid Glands are involved

IX. Approach: Thyroid pain

  1. Toxic appearing patient (fever, Leukocytosis, cervical adenopathy)
    1. Suppurative Thyroiditis or Infectious Thyroiditis
  2. History or local Radiation Therapy (e.g. I-131) or Trauma
    1. Radiation-Induced Thyroiditis
    2. Traumatic Thyroiditis (rare)
  3. Recent viral illness with decreased Serum TSH (and if ordered, increased Thyroglobulin)
    1. Subacute Granulomatous Thyroiditis (Subacute Thyroiditis, Giant Cell Thyroiditis)
  4. Sudden onset of Thyroid pain (with normal Thyroid Function Tests)
    1. Thyroid Hemorrhage

X. Approach: Painless Thyroiditis

  1. Taking Amiodarone, Denileukin, Interferon alfa, Interleukin-2, Kinase Inhibitors or Lithium?
    1. Drug-Induced Thyroiditis
  2. Recent pregnancy (in last year)
    1. Increased TSH
      1. Postpartum Thyroiditis (Hypothyroidism phase)
      2. Hashimoto Thyroiditis
    2. Decreased TSH with diffusely increased Radioactive Iodine Uptake Scan (RAIU)
      1. Graves Disease
    3. Decreased TSH with diffusely decreased Radioactive Iodine Uptake Scan (RAIU)
      1. Postpartum Thyroiditis (Hyperthyroidism phase)
  3. Increased TSH
    1. Hashimoto Thyroiditis
    2. Subacute Lymphocytic Thyroiditis or Silent Thyroiditis (Hypothyroidism phase)
  4. Decreased TSH with diffusely increased Radioactive Iodine Uptake Scan (RAIU)
    1. Graves Disease
  5. Decreased TSH with diffusely decreased Radioactive Iodine Uptake Scan (RAIU)
    1. Subacute Lymphocytic Thyroiditis or Silent Thyroiditis (Hyperthyroidism phase)

XI. Approach: Thyroiditis with Hyperthyroidism

  1. Step 1: Based on suppressed Serum TSH
    1. Confirm Hyperthyroidism with Free T4 and Free T3
  2. Step 2: Consider recent medical history
    1. Recent illness (Euthyroid Sick Syndrome)
    2. Malnutrition or Hyponatremia risk factors
    3. Medications (e.g. Corticosteroids, Opiates, Levodopa)
  3. Step 3: Consider severity of symptoms (in confirmed Hyperthyroidism with decreased TSH and increased Free T4)
    1. Consider Beta Blockers (e.g. Propranolol) in significant Hyperthyroidism related symptoms
  4. Step 4: Distinguish Graves Disease from other Hyperthyroidism causes
    1. Obtain Radioactive Iodine Uptake Scan (RAIU)

XII. Course

  1. Most Thyroiditis follows a triphasic course
    1. Hyperthyroidism phase
      1. Preformed Thyroid Hormone released from damaged Thyroid follicular cells
    2. Hypothyroidism phase
      1. Follows Thyroid Hormone store depletion
    3. Euthyroid phase
      1. Normalization of Thyroid function

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Related Studies

Ontology: Acute thyroiditis (C0001360)

Concepts Disease or Syndrome (T047)
ICD9 245.0
ICD10 E06.0
SnomedCT 154665005, 190295008, 190293001
English Acute thyroiditis NOS, acute thyroiditis, acute thyroiditis (diagnosis), Thyroiditis acute, thyroiditis acute, Acute thyroiditis NOS (disorder), Acute thyroiditis, Acute thyroiditis (disorder), acute; thyroiditis, thyroiditis; acute
Italian Tiroidite acuta
Dutch acute thyreoïditis, acuut; thyroïditis, thyroïditis; acuut, Acute thyroïditis, thyreoïditis acuut
German akute Thyreoiditis, Akute Thyreoiditis, Thyreoiditis akut
Japanese 急性甲状腺炎, キュウセイコウジョウセンエン
Czech Akutní zánět štítné žlázy, Akutní tyreoiditida
Korean 급성 갑상샘염
Hungarian Acut thyreoiditis, Heveny pajzsmirigy-gyulladás
Spanish tiroiditis aguda, SAI (trastorno), tiroiditis aguda, SAI, tiroiditis aguda (trastorno), tiroiditis aguda, Tiroiditis aguda
Portuguese Tiroidite aguda
French Thyroïdite aiguë

Ontology: Thyroiditis (C0040147)

Definition (CHV) inflammation of the thyroid gland
Definition (CHV) inflammation of the thyroid gland
Definition (NCI) Inflammation of the thyroid gland. This category includes Hashimoto thyroiditis, Riedel thyroiditis, acute thyroiditis, subacute thyroiditis, and radiation-induced thyroiditis.
Definition (NCI_NCI-GLOSS) Inflammation of the thyroid gland. Thyroiditis may be an autoimmune disease that affects the thyroid gland over time, causing hypothyroidism (too little thyroid hormone). A temporary form of thyroiditis may also occur after the birth of a baby, or when viral or bacterial infections spread to the thyroid.
Definition (CSP) inflammation of the thyroid gland.
Definition (MSH) Inflammatory diseases of the THYROID GLAND. Thyroiditis can be classified into acute (THYROIDITIS, SUPPURATIVE), subacute (granulomatous and lymphocytic), chronic fibrous (Riedel's), chronic lymphocytic (HASHIMOTO DISEASE), transient (POSTPARTUM THYROIDITIS), and other AUTOIMMUNE THYROIDITIS subtypes.
Concepts Disease or Syndrome (T047)
MSH D013966
ICD9 245.9, 245
ICD10 E06 , E06.9
SnomedCT 154668007, 190301009, 154664009, 82119001
English Thyroiditides, THYROIDITIS, Thyroiditis NOS, Thyroiditis, unspecified, Thyroiditis, thyroiditis, thyroiditis (diagnosis), Thyroiditis [Disease/Finding], unspecified thyroiditis, Thyroiditis NOS (disorder), Thyroiditis (disorder), Thyroiditis, NOS
French THYROIDITE, Thyroïdite SAI, Thyroïdite, non précisée, Thyroïdite
Spanish TIROIDITIS, Tiroiditis NEOM, Tiroiditis no especificada, tiroiditis, SAI (trastorno), Thyroiditis NOS, tiroiditis, SAI, tiroiditis (trastorno), tiroiditis, Tiroiditis
German THYREOIDITIS, Thyreoiditis, unspezifisch, Thyreoiditis NNB, Thyreoiditis, nicht naeher bezeichnet, Thyroiditis, Thyreoiditis
Dutch thyreoïditis NAO, thyreoïditis, niet-gespecificeerd, Thyroïditis, niet gespecificeerd, thyreoïditis, Thyreoiditis, Thyroïditis
Italian Tiroidite NAS, Tiroidite non specificata, Tiroidite
Portuguese Tiroidite NE, TIROIDITE, Tiroidite, Tireóide, Tireoidite
Japanese 甲状腺炎、詳細不明, 甲状腺炎, 甲状腺炎NOS, コウジョウセンエンショウサイフメイ, コウジョウセンエン, コウジョウセンエンNOS
Swedish Sköldkörtelinflammation
Czech tyreoiditida, štítná žláza - zánět, Zánět štítné žlázy, Tyreoiditida NOS, Tyreoiditida, blíže neurčená
Finnish Kilpirauhastulehdus
Russian TIREOIDIT, ТИРЕОИДИТ
Korean 상세불명의 갑상샘염, 갑상샘염
Croatian TIREOIDITIS
Polish Zapalenie tarczycy
Hungarian Thyreoiditis, Thyreoiditis, nem meghatározott, Thyreoiditis k.m.n.
Norwegian Skjoldbruskkjertelbetennelse, Tyreoiditt