Thyroiditis

Thyroiditis Microchapters
Patient Information
Overview
Classification Hashimoto's thyroiditis Riedel's thyroiditis De quervain thyroiditis Suppurative thyroiditis Postpartum thyroiditis
Differentiating Thyroiditis from Other Diseases
Diagnosis
Treatment

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Furqan M M. M.B.B.S[2], Usama Talib, BSc, MD [3]

Overview

Thyroiditis refers to an inflammation of the thyroid gland. It is classified into Hashimoto's thyroiditis, de Quervain's Thyroiditis, silent thyroiditis, postpartum thyroiditis, Riedel's thyroiditis, and suppurative thyroiditis. These forms of thyroiditis can be differentiated from each other on the basis of pathological and laboratory findings. Thyroiditis can lead to hypothyroidism or transient hyperthyroidism. The hypothyroid phase of thyroiditis results from the gradual depletion of stored thyroid hormones. Chronic hypothyroidism is predominantly associated with Hashimoto’s thyroiditis. However, all the types of thyroiditis may progress to permanent hypothyroidism. Painless sporadic thyroiditis (silent thyroiditis), painless postpartum thyroiditis, and painful subacute thyroiditis (de Quervain's thyroiditis) usually lead to transient hyperthyroidism (thyrotoxicosis) when the preformed thyroid hormones are released from the damaged gland. As thyroid hormone stores are depleted, there is often a progression through a period of euthyroidism to hypothyroidism. Suppurative thyroiditis is the result of an infection usually in the patients with preexisting thyroid disease (Hashimoto's thyroiditis, thyroid cancer, or multinodular goiter), immunosuppression, and congenital anomalies (pyriform sinus fistula). The diagnosis of thyroiditis is usually made on the physical examination, thyroid function tests, thyroid ultrasound, iodine uptake, thyroglobulin, and thyroid peroxidase antibodies. Histopathological analysis is also helpful to differentiate thyroiditis from other thyroid diseases. The treatment of thyroiditis is usually symptomatic. Beta blockers are used for the symptoms of thyrotoxicosis and levothyroxine is helpful to improve the symptoms of hypothyroidism. NSAIDs are helpful in alleviating the pain in de Quervain's thyroiditis and corticosteroids are specifically used in Riedel's thyroiditis. Antibiotics are usually reserved for the suppurative thyroiditis.

Classification

Thyroiditis is classified into the following types:

• Hashimoto's thyroiditis.
• DeQuervain's Thyroiditis or Granulomatous Thyroiditis
• Silent thyroiditis
• Postpartum thyroiditis
• Riedel's thyroiditis
• Suppurative thyroiditis

Thyroiditis

Hashimoto's thyroiditis

DeQuervain's Thyroiditis

Silent thyroiditis

Postpartum thyroiditis

Riedel's thyroiditis

Suppurative thyroiditis

Differentiating Thyroiditis from Other Diseases

Various forms of thyroiditis can be differentiated from each other on the basis of pathological and laboratory findings:

Conditions	Causes	Age at onset	Pathological findings	Diagnostic approach
Hashimoto's thyroiditis	Autoimmune	All ages, peak at 30-50	Lymphocytic infiltration Germinal centers Fibrosis (in some variants)	Increased TSH (hypothyroidism) TPO antibodies present in high titer I-123 uptake usually decreased
Painful subacute (De Quervain's) thyroiditis	Unknown	20-60	Giant cells Granulomas	Increased TSH (hypothyroidism) and/or Decreased TSH (Thyrotoxicosis) TPO antibodies absent or very low titer I-123 uptake decreased
Silent thyroiditis	Autoimmune	All ages, peak at 30-40	Lymphocytic infiltration Lymphoid follicles	Increased TSH (hypothyroidism) and/or Decreased TSH (transient hypothyroidism) TPO antibodies present in high titer I-123 uptake usually decreased
Postpartum thyroiditis	Autoimmune	Childbearing age	Lymphocytic infiltration	Increased TSH (hypothyroidism) and/or Decreased TSH (transient hypothyroidism) TPO antibodies present in high titer I-123 uptake usually decreased
Riedel's thyroiditis	Unknown	30-60	Dense fibrosis	Normal TSH (euthyroidism) TPO antibodies usually present I-123 uptake decreased or normal
Suppurative thyroiditis	Infection	Children, 20-40	Abscess formation	Normal TSH (euthyroidism) TPO antibodies absent I-123 uptake normal

Diagnosis

The following flowchart describes the clinical approach to the diagnosis of thyroiditis.

Stepwise clinical diagnosis of thyroiditis

Neck pain

Yes

No

RAIU*

Presenting symptoms and TFTs‡

Increased

Decreased

Hyperthyroid

Hypothyroid

Euthyroid

RAIU*

Suppurative thyroiditis

Hashimoto's thyroiditis

Increased

Decreased

Hashimoto's thyroiditis

Riedel's thyroiditis††

Graves disease†

De Quervain's thyroiditis Silent thyroiditis Postpartum thyroiditis

‡TFT; Thyroid function tests(TSH, T4, and T3), †Grave's disease is not a thyroiditis, *RAIU; Radioiodine uptake.††One third of Riedel's thyroiditis presents with hypothyroidism.
Table modified from

Treatment

Treatment of Hashimoto's thyroiditis

The drugs used in the treatment of Hashimoto's thyroiditis are:

1. Levothyroxine:
   • lifelong synthetic levothyroxine (L-T4) is used to treat the hypothyroidism in Hashimoto's disease.
   • Main goals of levothyroxine replacement therapy are:
     • Resolution of the hypothyroid symptoms and signs including biological and physiologic markers of hypothyroidism
     • Normalization of serum thyrotropin with improvement in thyroid hormone concentrations
     • To avoid overtreatment (iatrogenic thyrotoxicosis)
   • Side effects include atrial fibrillation and osteoporosis
2. Corticosteroids:
   • A short course of glucocorticoids can be used in the treatment of IgG4-related variant of Hashimoto's thyroiditis.
3. Selenium:
   • Dietary selenium supplementation is considered to be protective against the autoimmune diseases of the thyroid.

Drug Regimen for Hashimoto's thyroiditis

• Synthetic levothyroxine (L-T4) 1.6–1.8 μg/kg of body weight per day orally.

Treatment of de Quervain's thyroiditis thyroiditis

The drugs used in the treatment of de Quervain's thyroiditis are:

1. NSAIDs
2. Prednisone
3. Atenolol
4. Synthetic levothyroxine

Drug Regimens for de Quervain's thyroiditis

• For pain
  • Preferred regimen (1): Naproxen: 500 to 1000 mg per day in two divided doses
  • Preferred regimen (2): Ibuprofen: 1200 to 3200 mg per day in three or four divided doses
• For severe condition
  • Preferred regimen (1): Prednisone: 40 mg per day orally
• For hypothyroidism
• Preferred regimen (1): Synthetic levothyroxine (L-T4): 1.6–1.8 μg/kg per day orally
• For thyrotoxic symptoms
  • Preferred regimen (1): atenolol: 25-200mg per day orally
  • Preferred regimen (2): metoprolol: 25-200mg per day orally

Treatment of silent thyroiditis

The drugs used in the treatment of silent thyroiditis are:

1. Atenolol
2. Metoprolol
3. Synthetic levothyroxine

Drug Regimen for silent thyroidits

• For thyrotoxic symptoms
  • Preferred regimen (1): atenolol: 25-200mg per day orally
  • Preferred regimen (2): metoprolol: 25-200mg per day orally
• For hypothyroidism
• Preferred regimen (1): Synthetic levothyroxine (L-T4): 1.6–1.8 μg/kg per day orally

Treatment of Riedel's thyroidtis

• The drugs used in the treatment of silent thyroiditis are:

1. Corticosteroids
2. Tamoxifen
3. Mycophenolate mofetil(used in combination with corticosteroids)

Drug Regimens for Riedel's thyroidtis

The effectiveness of therapy and dosages for Riedel's thyroiditis have not yet been assessed completely. As a result, the exact dosage regimens and duration of therapy cannot be defined. The current recommendations are based on the clinical manifestations, associated conditions, and the response to treatment.

• Preferred regimen (1): Prednisone 15-60mg PO q24h for 6 months to 2 years
• Preferred regimen (2): Prednisone 500 mg PO q24h for 6 months to 2 years
• Alternative regimen (1): Tamoxifen 10-20 mg PO q24h for 6 months to 2 years
• Alternative regimen (1): Mycophenolate mofetil 1 g PO q12h for 6 months to 2 years

Related Chapters

• Hypothyroidism
• Hyperthyroidism
• Graves-Basedow disease

References

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