> Table of Contents > Thyroiditis
Robert A. Baldor, MD, FAAFP
image BASICS
Inflammation of the thyroid gland that may be painful or painless
  • Thyroiditis with thyroid pain
    • Subacute granulomatous thyroiditis (nonsuppurative thyroiditis, de Quervain thyroiditis, or giant cell thyroiditis): self-limited; viral URI prodrome, symptoms and signs of thyroid dysfunction (variable)
    • Infectious/suppurative thyroiditis
      • Bacterial, fungal, mycobacterial, or parasitic infection of the thyroid
      • Most commonly associated with Streptococcus pyogenes, Staphylococcus aureus, and Streptococcus pneumoniae
    • Radiation-induced thyroiditis: from radioactive iodine therapy (1%) or external irradiation for lymphoma and head/neck cancers
  • Thyroiditis with no thyroid pain
    • Hashimoto (autoimmune) thyroiditis (chronic lymphocytic thyroiditis): most common etiology of chronic hypothyroidism; autoimmune disease; 90% of patients with high-serum antithyroid peroxidase (TPO) antibodies
    • Postpartum thyroiditis: episode of thyrotoxicosis, hypothyroidism, or thyrotoxicosis followed by hypothyroidism in the 1st year postpartum or after spontaneous/induced abortion in women who were without clinically evident thyroid disease before pregnancy
    • Painless (silent) thyroiditis (subacute lymphocytic thyroiditis): mild hyperthyroidism, small painless goiter, and no Graves ophthalmopathy/pretibial myxedema
    • Riedel (fibrous) thyroiditis: rare inflammatory process involving the thyroid and surrounding cervical tissues; associated with various forms of systemic fibrosis; presents as a firm mass in the thyroid commonly associated with compressive symptoms (dyspnea, dysphagia, hoarseness, and aphonia) caused by local infiltration of the advancing fibrotic process with hypocalcemia and hypothyroidism
    • Drug-induced thyroiditis: interferon-&agr;, interleukin-2, amiodarone, or lithium
  • Subacute granulomatous thyroiditis: most common cause of thyroid pain; peaks during summer; incidence: 3/100,000/year; female > male (4:1); peak age: 40 to 50 years
  • Suppurative thyroiditis: commonly seen with preexisting thyroid disease/immunocompromise
  • Hashimoto thyroiditis: peak age of onset, 30 to 50 years; can occur in children; primarily a disease of women; female > male (7:1)
  • Postpartum thyroiditis: Female only; occurs within 12 months of pregnancy in 8-11% of pregnancies; occurs in 25% with type 1 diabetes mellitus; incidence is affected by genetic influences and iodine intake.
  • Painless (silent) thyroiditis: female > male (4:1) with peak age 30 to 40 years; common in areas of iodine sufficiency
  • Reidel thyroiditis: female > male (4:1); highest prevalence age 30 to 60 years
  • Hashimoto disease: Antithyroid antibodies may be produced in response to an environmental antigen and cross-react with thyroid proteins (molecular mimicry). Precipitating factors include infection, stress, sex steroids, pregnancy, iodine intake, and radiation exposure.
  • Subacute granulomatous thyroiditis: probably viral
  • Postpartum thyroiditis: autoimmunity-induced discharge of preformed hormone from the thyroid
  • Painless (silent) thyroiditis: autoimmune
Autoimmune thyroiditis is associated with the CT60 polymorphism of cytotoxic T-cell lymphocyte-associated antigen 4. Also associated with HLA-DR4, -DR5, and -DR6 in whites
  • Hashimoto disease: family history of thyroid/autoimmune disease, personal history of autoimmune disease (type 1 diabetes, celiac disease), high iodine intake, cigarette smoking, selenium deficiency
  • Subacute granulomatous thyroiditis: recent viral respiratory infection
  • Suppurative thyroiditis: congenital abnormalities (persistent thyroglossal duct/piriform sinus fistula), greater age, immunosuppression
  • Radiation-induced thyroiditis: high-dose irradiation, younger age, female sex, preexisting hypothyroidism
  • Postpartum thyroiditis: smoking, history of spontaneous/induced abortion
  • Painless (silent) thyroiditis: iodine-deficient areas
Selenium may decrease inflammatory activity in pregnant women with autoimmune hypothyroidism and may reduce postpartum thyroiditis risk in those positive for TPO antibodies.
Postpartum thyroiditis: family history of autoimmune thyroid disease; HLA-DRB, -DR4, and -DR5
  • Examine thyroid size, symmetry, and nodules.
    • Hashimoto disease: 90% have a symmetric, diffusely enlarged, painless gland, with a firm, pebbly texture; 10% have thyroid atrophy.
    • Postpartum thyroiditis: painless, small, nontender, firm goiter (2 to 6 months after delivery)
    • Reidel thyroiditis: rock-hard, wood-like, fixed, painless goiter, often accompanied by symptoms of esophageal/tracheal compression (stridor, dyspnea, a suffocating feeling, dysphagia, and hoarseness)
  • Signs of hypothyroid: delayed relaxation phase of deep tendon reflexes, nonpitting edema, dry skin, alopecia, bradycardia
  • Signs of hyperthyroid: moist palms, hyperreflexia, tachycardia/atrial fibrillation
Simple goiter; iodine-deficient/lithium-induced goiter; Graves disease; lymphoma; acute infectious thyroiditis; oropharynx and trachea infections; thyroid cancer; amiodarone; contrast dye; amyloid
  • Thyroid-stimulating hormone (TSH), anti-TPO antibodies
  • Hashimoto disease
    • High titers of anti-TPO antibodies
    • New subtype: IgG4 thyroiditis, which is histopathologically characterized by lymphoplasmacytic infiltration, fibrosis, increased numbers of IgG4-positive plasma cells, and high serum IgG4 levels; more closely associated with rapid progress, subclinical hypothyroidism, higher levels of circulating antibodies, and more diffuse low echogenicity (2)[C]
  • Subacute granulomatous thyroiditis
    • High T4, T3; low TSH during early stages and elevated later; TSH varies with phase (1)[C].
    • High thyroglobulin; normal levels of anti-TPO and antithyroglobulin antibodies (present in 25%, usually low titers)
    • Elevated erythrocyte sedimentation rate (ESR) (usually >50 mm/hr) and C-reactive protein; mild anemia and slight leukocytosis; LFTs are frequently abnormal during initial hyperthyroid phase and resolve over 1 to 2 months.
  • Suppurative thyroiditis
    • In the absence of preexisting thyroid disease, thyroid function is normal but hyper-/hypothyroidism may occur.
    • Elevated ESR and WBC with marked increase in left shift
    • Fine-needle aspiration (FNA) of the lesion with Gram stain and culture is the most useful diagnostic test.
  • Postpartum thyroiditis (3)[B]
    • Anti-TPO antibody positivity is the most useful marker for the prediction of postpartum thyroid dysfunction.
    • Women known to be anti-TPO-Ab + should have TSH measured at 6 to 12 weeks' gestation and at 6 months postpartum or as clinically indicated.
    • Thyrotoxic phase occurs 1 and 6 months postpartum (most commonly at 3 months) and usually lasts only 1 to 2 months.
    • Hypothyroidism occurs between 3 and 8 months (most commonly at 6 months).
    • Most patients (80%) have normal thyroid function at 1 year; 30-50% of patients develop permanent hypothyroidism within 9 years.
    • High thyroglobulin, normal ESR
  • P.1037

  • Painless (silent) thyroiditis
    • Hyperthyroid state in 5-20%: averages 3 to 4 months, and total duration of illness is <1 year, followed by hypothyroidism and then a return to normal state; some have primary/subclinical hypothyroidism.
    • ˜ 50% have anti-TPO antibodies (1)[C].
  • Reidel thyroiditis (4)[C]
    • Hypothyroidism due to extensive replacement of the gland by scar tissue. Anti-TPO antibodies are present in 2/3 of patients along with low radioactive iodine uptake (RAIU).
  • Drug-induced thyroiditis
    • Hyper-/hypothyroidism, low RAIU, and variable presence of anti-TPO antibodies
  • US: shows variable heterogeneous texture, hypoechogenic in subacute, painless (silent), and postpartum thyroiditis
  • Thyroid RAIU scan: decreased in all forms of thyroiditis but not helpful in establishing diagnosis of Hashimoto disease. High RAIU in hashitoxicosis, Graves disease
  • Random urine iodine measurement may be helpful to distinguish from other causes of low RAIU.
    • Urine iodine <500 &mgr;g/L (subacute granulomatous thyroiditis)
    • Urine iodine >1,000 &mgr;g/L (in patients with exposure to excess exogenous iodine/radiocontrast material)
Diagnostic Procedures/Other
  • Hashimoto with a dominant nodule should have FNA to rule out thyroid carcinoma.
  • Open biopsy is necessary for a definitive diagnosis of Reidel thyroiditis.
Test Interpretation
  • Hashimoto disease: lymphocytic infiltration with formation of Askanazy (Hürthle) cells, oxyphilic changes in follicular cells, fibrosis, thyroid atrophy
  • Subacute granulomatous thyroiditis: giant cells, mononuclear cell (granulomatous) infiltrate
  • Postpartum thyroiditis: lymphocytic infiltration, occasional germinal centers, disruption and collapse of thyroid follicles
  • Painless (silent) thyroiditis: lymphocytic infiltration, but without fibrosis, Askanazy cells, and extensive lymphoid follicle formation
Analgesics for pain; corticosteroids for severe granulomatous thyroiditis
  • Hashimoto disease (2)[C]
    • If hypothyroid/goitrous: levothyroxine (1.7 &mgr;g/kg/day for adults <50 years of age). If no cardiac complications and no adrenal insufficiency, 1/2 replacement dose and increase to full replacement in 10 days.
      • If >50 years of age or heart disease and/or adrenal insufficiency, begin with 25 &mgr;g/day and titrate to TSH of lower limit normal range.
  • If thyrotoxic and symptomatic: propylthiouracil and propranolol
  • An elevated TSH level in a woman who is pregnant or attempting to become pregnant is an indication for thyroid replacement.
  • Subacute granulomatous thyroiditis
    • Anti-inflammatory agents for 2 to 8 weeks (NSAIDs or aspirin)
    • Pain with no improvement in 2 to 3 days after NSAID use: Prednisone 40 mg/day; should result in pain relief in 1 to 2 days; if not, question diagnosis.
    • Severe pain: prednisone 40 to 60 mg/day discontinued over 4 to 6 weeks. If pain recurs, increase dose for several weeks and then taper.
    • Symptomatic hyperthyroidism: &bgr;-blockers while thyrotoxic (propranolol 40 to 120 mg/day)
    • Symptomatic hypothyroid phase: Levothyroxine, as mentioned earlier, target TSH in the normal range.
  • Suppurative thyroiditis
    • Parenteral empiric, broad-spectrum antibiotics, and surgical drainage
  • Painless (silent) thyroiditis
    • No treatment needed.
    • If symptomatic during hyperthyroid state, treat with &bgr;-blocker (propranolol 40 to 120 mg/day).
    • Prednisone shortens the period of hyperthyroidism. Monitor TSH every 4 to 8 weeks to confirm resolution.
    • Treat hypothyroid symptoms and asymptomatic patients with TSH >10 mU/L with levothyroxine (50 to 100 &mgr;g/day), to be discontinued after 3 to 6 months.
  • Postpartum thyroiditis (5)[C]
    • Treat symptomatic hyper-/hypothyroid state. Most do not need treatment.
    • Caution in breastfeeding mothers because &bgr;-blockers are secreted into breast milk.
    • For symptomatic hypothyroidism, treat with levothyroxine. Otherwise, remonitor in 4 to 8 weeks. Taper replacement hormone after 6 months if thyroid function has normalized.
  • Reidel thyroiditis (4)[C]
    • Corticosteroids in early stages but controversial thereafter. Prednisone 10 to 20 mg/day for 4 to 6 months, possibly continued thereafter if effective
    • Long-term anti-inflammatory medications to arrest progression and maintain a symptom-free course
    • Tamoxifen 10 to 20 mg twice daily as monotherapy or in conjunction with prednisone reduces mass size and clinical symptoms.
    • Methotrexate is used with some success.
    • Reduction of goiter seen with a combination of mycophenolate mofetil (1 g BID) and 100 mg/day prednisone
    • Debulking surgery is limited to isthmusectomy to relieve constrictive pressure when total thyroidectomy is not possible.
  • Drug-induced thyroiditis
    • Discontinue offending drug.
Enlarged painful thyroid or tracheal compression
Patient Monitoring
  • Hashimoto disease: Repeat thyroid function tests every 3 to 12 months.
  • Subacute granulomatous thyroiditis: Repeat thyroid function tests every 3 to 6 weeks until euthyroid, then every 6 to 12 months.
  • Postpartum thyroiditis: Check TSH annually.
  • Reidel thyroiditis: CT of cervical mediastinal region is recommended.
  • TSH every 6 months in patients on amiodarone
Pregnancy Considerations
  • Avoid radioisotope scanning if possible.
  • Keep TSH maximally suppressed.
  • If using RAIU scan, discard breast milk for 2 days because RAI is secreted in breast milk.
  • Hashimoto disease: persistent goiter; eventual thyroid failure
  • Subacute granulomatous thyroiditis: 5-15% hypothyroid beyond a year: Some with eventual return to normal; remission may be slower in the elderly; recurrence rate: 1-4% after a year
  • Painless (silent) thyroiditis: 10-20% hypothyroid beyond a year; recurrence rate 5-10% (much higher in Japan)
  • Postpartum thyroiditis: 15-50% hypothyroid beyond a year; women may be euthyroid/continue to be hypothyroid at the end of 1st postpartum year. 70% recurrence rate in subsequent pregnancies; substantial risk exists for later development of hypothyroidism/goiter.
1. Samuels MH. Subacute, silent, and postpartum thyroiditis. Med Clin North Am. 2012;96(2):223-233.
2. Li Y, Nishihara E, Kakudo K. Hashimoto's thyroiditis: old concepts and new insights. Curr Opin Rheumatol. 2011;23(1):102-107.
3. De Groot L, Abalovich M, Alexander EK, et al. Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2012;97(8):2543-2565. doi:10.1210/jc.2011-2803
4. Hennessey JV. Clinical review: Riedel's thyroiditis: a clinical review. J Clin Endocrinol Metab. 2011;96(10):3031-3041.
5. Reid SM, Middleton P, Cossich MC, et al. Interventions for clinical and subclinical hypothyroidism in pregnancy. Cochrane Database Syst Rev. 2010;(7):CD007752.
Additional Reading
Duntas LH. Selenium and the thyroid: a close-knit connection. J Clin Endocrinol Metab. 2010;95(12): 5180-5188.
See Also
Hyperthyroidism; Hypothyroidism, Adult
  • E06.9 Thyroiditis, unspecified
  • E06.1 Subacute thyroiditis
  • E06.0 Acute thyroiditis
Clinical Pearls
  • TSH elevation above the normal range indicates a hypothyroid state; suppressed TSH indicates hyperthyroid state. Follow up with free T3/T4 determination.
  • Follow patients on thyroid replacement with periodic TSH level.