Thyroidits

Thyroiditis refers to inflammation of the thyroid gland and can be categorized based on the onset of symptoms, underlying etiology, and clinical presentation. This condition can arise from various causes, including autoimmune disorders, infections, medications, and fibrosis.

• Autoimmune Thyroiditis: This includes Hashimoto's thyroiditis, Graves' disease, postpartum thyroiditis, and painless sporadic thyroiditis, where the immune system mistakenly attacks the thyroid gland.
• Infectious Thyroiditis: Painful subacute thyroiditis (De Quervain's thyroiditis) and suppurative thyroiditis result from infections that cause inflammation and pain in the thyroid gland.
• Drug-induced Thyroiditis: Certain medications, such as amiodarone, lithium, interferons, and interleukin-2, can trigger thyroid inflammation.
• Fibrotic Thyroiditis: Riedel's thyroiditis is a rare form characterized by fibrosis of the thyroid gland, leading to a hard, fixed thyroid mass.

The most common forms encountered by family physicians include Hashimoto thyroiditis, postpartum thyroiditis, and subacute thyroiditis. Most forms of thyroiditis exhibit a triphasic pattern of thyroid dysfunction:

1. Hyperthyroidism (Thyrotoxicosis): Initial phase due to the release of preformed thyroid hormone from damaged thyroid cells.
2. Hypothyroidism: Occurs when thyroid hormone stores are depleted.
3. Restoration: Normal thyroid function eventually returns in many cases, although some patients may develop permanent hypothyroidism.