Subacute Thyroiditis—Still a Diagnostic Challenge: Data from an Observational Study

Abstract

Background: Subacute thyroiditis (SAT) is a relatively common cause of thyroid disease. However, only a few studies evaluating SAT have been published in recent years with varying diagnostic criteria. We evaluate the clinical presentation and long-term outcome of isotope scan-confirmed SAT. Methods: A retrospective study of 38 patients with isotope scan-confirmed SAT was performed at a single isotope department. All patients were contacted for long-term follow-up. Results: The female/male ratio was 1.4:1, and mean age was 47 ± 14 years and 62 ± 12 years in women and men, respectively (p = 0.002). Almost half of the cases (42%) occurred during the summer. The most common symptoms were neck pain (74%) and weakness (61%). Palpitations, weight loss, heat intolerance, and sweating appeared in 50%, 42%, 21%, and 21%, respectively. Only half of the patients reported fever. TSH level was low in all patients, and mean FT4 and FT3 level were about twice the upper limit of normal range. Elevated CRP and ESR occurred in the majority (88%) of patients. The mean time period between the first clinic visit and performing thyroid function tests was 8 ± 7 days. One-third of the patients initially received a diagnosis of upper respiratory tract infection (URI). NSAIDs and steroids were prescribed to 47% and 8% of patients, respectively. Long-term follow-up of 33.5 months (range 9–52) revealed that 25% remained with subclinical or overt hypothyroidism. Conclusions: These data demonstrate that although SAT is a common entity, there is still a significant delay in diagnosis, and in a third of our patients, the initial diagnosis was URI, with 25% developing long-term hypothyroidism.

Retrospective observation of subacute thyroiditis before and during the COVID-19 vaccination campaign in a single secondary endocrine centre in the Savona district, Liguria, Italy

“…SAT affects women almost 4 to 5 times as often as men and typically occurs between 25 and 35 years of age (1), although higher ages on SAT presentation have been reported [ 7 , 8 ]. SAT after SARS-CoV-2 vaccines seems preferentially to involve women [ 3 ], and indeed, all 7 cases observed by us in 2021 involved women.…”

Neck Pain and Symptomatic Hypothyroidism: An Atypical Presentation of Subacute Thyroiditis

“…SAT has three hallmark phases: thyrotoxicosis, hypothyroidism, and euthyroid. Upon initial destruction of the thyroid follicles, patients present with symptoms of hyperthyroidism such as palpitations, weight loss, heat intolerance, and diaphoresis [ 4 ]. This phase typically peaks at one week, as the stored thyroid hormone is depleted [ 5 ].…”

“…This stage can range from weeks to months, as the follicular fibrosis heals and the hypothalamic pituitary thyroid axis adjusts. While most patients return to the euthyroid state after the resolution of their symptoms, up to 25 percent of patients may remain permanently hypothyroid [ 2 , 4 ]. The likelihood of permanent hypothyroidism is not correlated with the severity of SAT [ 4 ].…”

“…While most patients return to the euthyroid state after the resolution of their symptoms, up to 25 percent of patients may remain permanently hypothyroid [ 2 , 4 ]. The likelihood of permanent hypothyroidism is not correlated with the severity of SAT [ 4 ]. Although it is rare, up to 20% of patients can experience recurrence of SAT [ 4 , 6 ].…”

The value of FT4/TSH ratio in the differential diagnosis of Graves’ disease and subacute thyroiditis

“…Menstrual cycle disturbances can occur in female and erectile dysfunction in male. ST, also known as granulomatous thyroiditis, giant cell thyroiditis, is the result of an inflammatory thyroid process of unknown etiology (6). The most common clinical manifestations include neck pain with tenderness and general fatigue.…”