Which condition is commonly associated with secondary subacute thyroiditis?

Secondary subacute thyroiditis is typically linked with a viral infection or a post-viral inflammatory response, most commonly associated with DeQuervain's syndrome (also known as subacute granulomatous thyroiditis). This condition usually occurs after a recent upper respiratory tract infection, leading to inflammation in the thyroid gland that can cause pain and dysfunction.

The association with DeQuervain's syndrome arises due to its nature of presenting as a painful, inflamed thyroid gland and its often self-limiting course, which differentiates it from other thyroid disorders. In contrast, conditions like Graves' disease and Hashimoto's disease are primary thyroid disorders characterized by their autoimmune nature and do not typically lead to the transient inflammation observed in subacute thyroiditis. Courvoisier's syndrome, which relates to gallbladder enlargement due to obstructed bile duct, is not connected to thyroid disorders at all. Understanding the nuances of these conditions helps clarify why DeQuervain's syndrome is the correct association with secondary subacute thyroiditis.