High prevalence of subacute thyroiditis during summer season in Italy

Subacute Thyroiditis Masquerading as Fever of Unknown Origin

Subacute thyroiditis (SAT) is an inflammatory disease of the thyroid gland. It can present with overlapping features of other etiology of thyroiditis. It can present with thyroid enlargement and systemic symptoms such as fever as well as neck pain and may be confused with infectious thyroiditis. It can be difficult to diagnose and present as fever of unknown origin (FUO). A good history, physical examination, laboratory investigation, as well as imaging may aid in the correct diagnosis and prevent the inappropriate use of antibiotics. Treatment is usually with nonsteroidal anti-inflammatory drugs (NSAIDs) as well as corticosteroids. We herein present a case of SAT presenting as FUO. We highlighted the importance of proper clinical evaluation, the importance of thyroid imaging, and how to differentiate other forms of thyroiditis.

Subacute Thyroiditis in Active COVID-19 Infection: A Report of Two Cases With a Systematic Review of the Literature

Subacute thyroiditis (SAT) is a self-limiting inflammatory condition of the thyroid gland with distinct symptoms and a predictable outcome. During the current COVID-19 pandemic, there have been multiple isolated reports of SAT either during the active viral illness or following recovery. Here, we report two such cases of COVID-19 infection presenting with SAT. A 65-year-old male presented with a two-week history of anterior neck pain, odynophagia, high-grade fever (38.9°C), sweating, palpitations, and tremulousness. At physical examination, the patient presented with a slightly increased heart rate and a tender and enlarged thyroid on palpation. Laboratory examination showed high C-reactive protein levels, with elevated erythrocyte sedimentation rate, and thyroid function tests were suggestive of thyrotoxicosis. Ultrasonography showed a heterogeneous thyroid gland with ill-defined hypoechoic areas, and thyroid scintigraphy showed reduced uptake, confirming the diagnosis of SAT. In another case, a 52-year-old male presented with fever, cough, and myalgias, and was diagnosed with mild COVID-19 pneumonia, and managed conservatively. After two weeks, the patient had a recurrence of high-grade fever, odynophagia, palpitations, and tremors. Examination revealed tachycardia, hyperhidrosis, and a tender and enlarged thyroid on palpation. Thyroid function tests revealed low thyroid-stimulating hormone, with normal total T4 and total T3. Ultrasonography examination showed a heterogeneous thyroid gland with bilateral ill-defined hypoechoic areas. In our systematic review, including 103 SAT cases, it has been suggested that SAT should be recognized as an uncommon extra-pulmonary clinical manifestation of COVID-19 infection and clinicians need to be aware of the association. Pending larger multicentric studies, management of the condition has to be on a case-by-case basis.

Inflammatory and Infectious Disorders in Endocrine Pathology

A variety of inflammatory conditions may directly involve the endocrine glands, leading to endocrine dysfunction that can cause severe consequences on patients' health, if left untreated. Inflammation of the endocrine system may be caused by either infectious agents or other mechanisms, including autoimmune and other immune-mediated processes. Not infrequently, inflammatory and infectious diseases may appear as tumor-like lesions of endocrine organs and simulate neoplastic processes. These diseases may be clinically under-recognized and not infrequently the diagnosis is suggested on pathological samples. Thus, the pathologist should be aware of the basic principles of their pathogenesis, as well as of their morphological features, clinicopathological correlates, and differential diagnosis. Interestingly, several systemic inflammatory conditions show a peculiar tropism to the endocrine system as a whole. In turn, organ-specific inflammatory disorders are observed in endocrine glands. This review will focus on the morphological aspects and clinicopathological features of infectious diseases, autoimmune disorders, drug-induced inflammatory reactions, IgG4-related disease, and other inflammatory disorders involving the endocrine system. A mixed entity-based and organ-based approach will be used, with the aim to provide the practicing pathologist with a comprehensive and practical guide to the diagnosis of infectious and inflammatory disorders of the endocrine system.

Impact of the COVID-19 pandemic on the incidence, seasonal distribution, and characteristics of subacute thyroiditis

PURPOSE

An increasing number of cases of subacute thyroiditis (SAT) related to the coronavirus disease 2019 (COVID-19) and its vaccines continue to be published. The aim of this study was to investigate any change in the incidence and characteristics of SAT by comparing the pre-pandemic and pandemic periods.

METHODS

This retrospective, single-center study included 432 newly-diagnosed SAT patients between January 2018 and December 2021. The annual frequency of SAT was calculated as the number of newly-diagnosed SAT cases divided by the total number of outpatients that year.

RESULTS

The frequencies of newly-diagnosed SAT were 0.136% in 2018, 0.127% in 2019, 0.157% in 2020, and 0.114% in 2021 (p = 0.19). While SAT patients were clustered in the autumn (35.1%) in 2018 and 2019, it was found that this cluster shifted to the winter (33.0%) in 2020 and 2021, in parallel with COVID-19 case peaks (p = 0.017). The patients were separated into two groups as pre-COVID-19 pandemic SAT (n = 272) and COVID-19 pandemic SAT (n = 160). The mean ages of the groups were similar. There were more male patients in the COVID-19 pandemic SAT group than in the pre-pandemic group (30.6% vs. 18.7%, p = 0.005). Frequencies of overt hyperthyroidism and median free-thyroxine levels were significantly higher in the COVID-19 pandemic SAT group (p = 0.029, p = 0.001). Treatment modalities, recurrence rates, and permanent hypothyroidism were similar in both groups.

CONCLUSION

With the COVID-19 pandemic, although there was a change in seasonal variation of SAT and an increase in the number of male patients, there was no change in the incidence and clinical course of SAT.

Incidence of Subacute Thyroiditis During the COVID-19 Pandemic in South Korea Using the National Health Insurance Service Database

Background: Subacute thyroiditis (SAT) is a thyroid disease initiated by viral infection. Whether severe acute respiratory syndrome coronavirus 2 infection can cause SAT is unclear. This study investigated changes in the nationwide incidence of SAT during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This is a retrospective, cross-sectional population-based study. Data regarding SAT and related viral diseases, including COVID-19, from 2017 to 2020 were collected from the National Health Insurance Service and Korea Disease Control and Prevention Agency databases. Results: In a total of 15,447 patients, 2484 men and 12,963 women diagnosed with SAT from 2017 to 2020 were included in this study. The incidence of SAT was significantly higher in 2020 than in 2017-2019 (8.30 vs. 7.27 per 100,000 persons, p < 0.001), while the incidence of SAT-related respiratory viral diseases, except for COVID-19, markedly decreased in 2020. The peak age of SAT incidence in 2020 was 50-59 years, and the women-to-men ratio was 5.4 (similar to that in 2017-2019). Corticosteroids were prescribed more often (72% vs. 58%, p < 0.001), and the prescription rate exceeding 1 month was significantly higher (45% vs. 40%, p < 0.01) in 2020 than in 2017-2019. Conclusions: The incidence of SAT increased in 2020 in association with COVID-19. A diagnostic approach to COVID-19 needs to be considered in patients with SAT during the COVID-19 pandemic.

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

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.

The Old and the New in Subacute Thyroiditis: An Integrative Review

Subacute thyroiditis (SAT) is the most common cause of neck pain and thyrotoxicosis. Although this disease was recognized already by the end of the 18th century, new concepts regarding pathogenesis have emerged in recent years. Moreover, in the last two years, literature on SAT has increased significantly due to articles describing the possible connection with coronavirus disease 2019 (COVID-19). This integrative review depicts old and new concepts of this disease, proposing a detailed overview of pathogenesis, a practical approach to diagnosis and treatment, and a thorough description of the latest discoveries regarding the association of SAT with COVID-19.

SARS-CoV-2 vaccine-associated subacute thyroiditis: insights from a systematic review

PURPOSE

To perform a systematic review on published cases of subacute thyroiditis (SAT) secondary to SARS-CoV-2 vaccination, to highlight main features and increase the awareness of this condition.

METHODS

Original reports of SAT developed after SARS-CoV-2 vaccination (mRNA, viral vector, or inactivated virus vaccines) were retrieved from a search of electronic databases. Individual patient data on demographics, medical history, type of vaccine, workup and therapies were collected. Wilcoxon rank-sum, Kruskal-Wallis and chi-squared tests were employed for comparisons.

RESULTS

30 articles including 48 reports were retrieved, 3 additional cases evaluated by the Authors were described and included for analysis. Of the 51 patients, 38 (74.5%) were women, median age was 39.5 years (IQR 34-47). Patients developed SAT after a median of 10 days (IQR 4-14) after the vaccine shot. Baseline thyroid exams revealed thyrotoxicosis in 88.2% of patients, decreasing at 31.6% at follow-up. Corticosteroids were used in 56.4% of treated patients. Patients undergoing non-mRNA vaccines were most frequently Asian (p = 0.019) and reported more frequently weight loss (p = 0.021). All patients with a previous diagnosis of thyroid disease belonged to the mRNA vaccine group.

CONCLUSION

SARS-CoV-2 vaccine-associated SAT is a novel entity that should be acknowledged by physicians. Previous history of thyroid disease may predispose to develop SAT after mRNA vaccines, but further studies and larger cohorts are needed to verify this suggestion. SARS-CoV-2 vaccine-associated SAT is usually of mild/moderate severity and could be easily treated in most cases, thus it should not raise any concern regarding the need to be vaccinated.

Subacute thyroiditis after SARS-CoV-2 BNT162b2 vaccine in a multiple myeloma patient

Viral infections emerge in the pathogenesis of subacute thyroiditis. Aside from this, subacute thyroiditis following vaccines utilizing inactivated viruses has been shown on rare occasions. Due to the COVID-19 pandemic, several vaccines have been developed all over the world; mass and unprecedented vaccination has thus been initiated. However, it is known that cases such as subacute thyroiditis have been reported, albeit rarely, after administration of COVID-19 vaccines. In this case report, we present a 59-year-old patient with multiple myeloma developing subacute thyroiditis following BNT162b2 vaccine. Patient had swelling in the neck, and his symptoms were controlled with non-steroidal anti-inflammatory drugs. Subacute thyroiditis following administration of the COVID-19 vaccine is rare; however, it is likely an under-reported condition that is difficult to detect. Clinicians should stay informed and have increased awareness of post-COVID-19 vaccine subacute thyroiditis.

Two Case Reports of Subacute Thyroiditis after Receiving Vaccine for COVID-19

The ongoing COVID-19 pandemic, caused by a coronavirus named SARS-CoV-2, has struck the planet with great force. As of December 2019, the virus has made its devasting route across all continents . In January 2022, the World Health Organization (WHO) registered over 5.5 million COVID-19 related deaths. Most of these people had suffered from pneumonia and acute respiratory distress syndrome , and in some cases, extensive damage to all organ systems. To get hold of this pandemic, it was vital to find effective vaccines against it. The two vaccine candidates BNT162b2 (BioNTech/Pfizer) and ChAdOx1 (University of Oxford and AstraZeneca) offer a high level of protection against COVID-19 by providing immunity due to antibody production against the spike protein of SARS-CoV-2. In addition to general side effects, immunological side effects such as subacute thyroiditis can follow the vaccination. This transient inflammatory condition of the thyroid gland is characterized with hyperthyroxinemia, inflammation, pain, and tenderness in the thyroid region, as well as an elevation of serum thyroglobulin concentration. There are only a few reports on the occurrence of this disease after receiving a COVID-19 vaccine. We present two cases of subacute thyroiditis after vaccination with the vaccines BNT162b2 and ChAdOx1 and try to enlighten the problem of immunological phenomena after vaccination. It must be discussed whether cross-reactivity of the spike protein and tissue proteins such as thyroid peroxidase (TPO), an “autoimmune/inflammatory syndrome by adjuvants” (ASIA), or the circulating spike protein itself after vaccination are responsible for the SAT.

Early Thyroid Volume Reduction in Subacute Thyroiditis Can be a Potential Indicator for Hypothyroidism

BACKGROUND

Thyroid volume has been reported to decrease significantly after episodes of subacute thyroiditis (SAT); however, the relationship between thyroid volume and hypothyroidism remains unclear. This study assessed the association between thyroid volume changes and the hypothyroid phase in patients with SAT, a condition that can progress to persistent hypothyroidism.

METHODS

This retrospective study evaluated 37 patients diagnosed with SAT at the Department of Endocrinology and Metabolism of Chonnam National University Hwasun Hospital (CNUHH) between 2016 and 2021. Since we could not determine the clinical characteristics of patients with SAT before their episodes, 120 healthy individuals who underwent thyroid ultrasonography during regular check-ups from 2019 to 2021 at CNUHH were selected for comparison. Subgroup analyses were performed on patients with SAT with and without the hypothyroid phase during their clinical course.

RESULTS

Thyroid volume was significantly greater in SAT patients at the first visit than in controls (p<0.05), and it decreased constantly throughout the follow-up period. Subgroup analysis showed that the initial thyroid volumes were similar in patients with SAT with and without the hypothyroid phase. However, SAT patients with the hypothyroid phase had significantly smaller thyroid volumes at the 1 month (p=0.025) and 3 month (p=0.006) follow-up visits. The reduction rate of the thyroid volume was significantly different within the first month (p=0.009).

CONCLUSION

A greater reduction in thyroid volume in SAT patients within 1 month of episode had a higher chance of developing a subsequent hypothyroid phase, which can lead to persistent hypothyroidism. Serial thyroid ultrasonography in patients with SAT, especially within the first month, may help in predicting the disease course of SAT.

Subacute thyroiditis after SARS-CoV-2 infection

Viral infections are considered as etiologic factors of subacute thyroiditis. The true incidence of subacute thyroiditis, caused by SARS-CoV-2 infection, is probably considerable since it is often masked by more dramatic affection of the respiratory system. This report presents two female patients who developed de Quervain's thyroiditis after COVID-19 disease.

Incidence of De Quervain's thyroiditis during the COVID-19 pandemic in an area heavily affected by Sars-CoV-2 infection

PURPOSE

To evaluate the possible association between Covid-19 infection and subacute thyroiditis.

METHODS

We reviewed the medical and imaging records of patients referred to our Department's outpatient setting dedicated to 'thyroid emergency' (records with a 'bollino verde'-green sticker, classifed as urgent) from April 2020 to October 2020. This outpatient clinic is devoted to patients requiring evaluation for severe hypothyroidism, thyrotoxicosis and neck discomfort or pain. All patients with a newly-diagnosed subacute thyroiditis were selected. The data of all patients receiving a diagnosis of subacute thyroiditis was collected retrospectively, taking into account the same period of time (April-October) and starting from 2016.

RESULTS

During the COVID-19 outbreak in our region (April 2020 to October 2020) 396 patients attended the outpatient emergency clinic. Among them, 10 (2.5%) patients received a diagnosis of subacute thyroiditis. In a single patient, a 44-year-old man, a COVID-19 pulmonary infection had been diagnosed 7 weeks before the diagnosis of subacute thyroiditis. All of the remaining patients were and remain COVID-19 free as confirmed by telephone interview. The percentage of patients who received a diagnosis of subacute thyroiditis in the same period starting from 2016 was very similar (2.9%, 2.9%, 2.6% and 3.0% in 2016, 2017, 2018 and 2019, respectively).

CONCLUSIONS

Our data do not show an increase in the incidence of subacute thyroiditis in the Brescia area, a region with the highest prevalence of COVID-19 in Italy during the period of the pandemic outbreak.

Thyroiditis following vaccination against COVID-19: Report of two cases and review of the literature

Introduction

Immune response following viral infections has been suggested as a probable mechanism leading to subacute thyroiditis (SAT). A few cases of SAT following SARS-CoV-2 infection have been described since the outbreak of the pandemic in 2019. Cases of SAT after vaccination against influenza have also been reported. We describe two female patients with thyroiditis after vaccination against SARS-CoV-2.

Presentation of cases

The first patient presented with fever and pain in the thyroid area typical of SAT two weeks after vaccination with the BNT162B2 mRNA (Pfizer-BioNTech) COVID-19 vaccine. The second patient presented with biochemical and imaging features consistent with silent thyroiditis three weeks after vaccination with the ChAdOx1-S (AstraZeneca) vaccine. Both patients were asymptomatic prior to vaccination and PCR of nasopharyngeal swab for SARS-CoV-2 and other respiratory viruses associated with SAT was negative. Serology testing for measles, mumps, rubella, CMV and EBV viruses was suggestive of immunity. Antibody titre against spike S protein of SARS-CoV-2 was measured for both patients and was indicative of adequate post vaccination antibody response. Two months after initial assessment, both patients were euthyroid and asymptomatic.

Conclusions

Subacute as well as silent thyroiditis may rarely occur after vaccination against COVID-19. Further research is needed to investigate the prevalence and pathogenesis of thyroid dysfunction following vaccination against COVID-19.

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Thyroid function abnormalities are common in COVID-19 patients.

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Thyroiditis is a rare complication of influenza, HPV and HBV vaccination.

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We report two cases of thyroiditis after vaccination against COVID-19.

Subacute Thyroiditis During the SARS-CoV-2 Pandemic

Context

Acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been related to subacute thyroiditis (SAT).

Objective

We compared SAT cases during the SARS-CoV-2 pandemic to those observed in the previous years.

Methods

A cross-sectional, retrospective study was conducted at the Endocrinology Unit of University Hospital of Pisa, Italy. We included all patients observed from January 2016 to December 2020 because of an untreated SAT, who had developed the disease within 15 days prior to the visit. SAT cases from 2016 to 2019 (N = 152) are referred to as pre-SARS-CoV-2, while 2020 SAT patients are classified as pos-SARS-CoV-2 (N = 18) or neg-SARS-CoV-2 (N = 28), according to positive or negative SARS-CoV-2 testing performed up to 45 days from SAT onset.

Results

While during 2016-2019, most SAT cases were observed in the third quarter, in 2020, 2 peaks were seen, superimposable to the SARS-CoV-2 outbreaks in the second and the fourth quarters. In the second and fourth quarters of 2020, we observed higher levels of free thyroxine (FT4), C-reactive protein (CRP), and thyroglobulin (Tg) compared with the same quarters of the years 2016-2019. Pos-SARS-CoV-2 patients had higher FT4 (28.4 vs 24.1 nmol/L), CRP (8.5 vs 3.6 mg/L), and Tg (155 vs 60 µg/L) (P < 0.05 for all) and more frequently had hypothyroidism (13/15 vs 30/152 at 3 months) (P < 0.001) than pre-SARS-CoV-2 patients. Neg-SARS-CoV-2 patients showed a clinical picture intermediate between the other 2 groups.

Conclusion

The SARS-CoV-2 pandemic has caused a shift in the annual timing and severity of SAT cases.

C-reactive protein and thyroid-stimulating hormone levels as risk factors for hypothyroidism in patients with subacute thyroiditis

OBJECTIVE

This study was designed to explore the relationships between the clinical characteristics and outcomes of patients with subacute thyroiditis (SAT).

DESIGN

This is a single-center retrospective study.

PATIENTS

Eighty-nine patients with SAT who were hospitalized in the Sir Run Run Shaw Hospital in Zhejiang, China, from October 2014 to September 2020 were included.

METHODS

The Mann-Whitney U-test, chi-square test, and Cox regression analysis were conducted to identify the relationships between clinical characteristics and outcomes. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff levels of C-reactive protein (CRP) and thyroid-stimulating hormone (TSH).

RESULTS

The hypothyroidism and recurrence rates were 15.7 and 16.9%, respectively. CRP (≥72.0 mg/L), TSH (<0.02 mIU/L), and free triiodothyronine (fT3) (≥4.10 pg/mL) were associated with hypothyroidism. The cutoff level was 97.80 mg/L for CRP (area under the curve (AUC), 0.717, P = 0.014; sensitivity, 57.1%; specificity, 84.0%) and 0.10 mIU/L for TSH (AUC, 0.752, P = 0.004; sensitivity, 100%; specificity, 46.0%) by ROC curve analysis for hypothyroidism. The factors under study were not associated with recurrence.

CONCLUSION

CRP and TSH were risk factors for hypothyroidism in SAT. Thyroid functions should be monitored closely for the early detection of hypothyroidism, especially in patients with CRP levels of more than 97.80 mg/L and TSH levels of less than 0.10 mIU/L.

Thyroid hormone alterations in critically and non-critically ill patients with SARS-CoV-2 infection

OBJECTIVE

Following the evolution of COVID-19 pandemic, reports pointed on a high prevalence of thyroiditis-related thyrotoxicosis. Interpretation of thyroid tests during illness, however, is hampered by changes occurring in the context of non-thyroidal illness syndrome (NTIS). In order to elucidate these findings, we studied thyroid function in carefully selected cohorts of COVID-19 positive and negative patients.

DESIGN

Cohort observational study.

METHODS

We measured TSH, FT4, T3 within 24 h of admission in 196 patients without thyroid disease and/or confounding medications. In this study, 102 patients were SARS-CoV-2 positive; 41 admitted in the ICU, 46 in the ward and 15 outpatients. Controls consisted of 94 SARS-CoV-2 negative patients; 39 in the ICU and 55 in the ward. We designated the thyroid hormone patterns as consistent with NTIS, thyrotoxicosis and hypothyroidism.

RESULTS

A NTIS pattern was encountered in 60% of ICU and 36% of ward patients, with similar frequencies between SARS-CoV-2 positive and negative patients (46.0% vs 46.8%, P = NS). A thyrotoxicosis pattern was observed in 14.6% SARS-CoV-2 ICU patients vs 7.7% in ICU negative (P = NS) and, overall in 8.8% of SARS-CoV-2 positive vs 7.4% of negative patients. In these patients, thyroglobulin levels were similar to those with normal thyroid function or NTIS. The hypothyroidism pattern was rare.

CONCLUSIONS

NTIS pattern is common and relates to the severity of disease rather than SARS-CoV-2 infection. A thyrotoxicosis pattern is less frequently observed with similar frequency between patients with and without COVID-19. It is suggested that thyroid hormone monitoring in COVID-19 should not differ from other critically ill patients.

Subacute Thyroiditis during the COVID-19 Pandemic: Searching for a Clinical Association with SARS-CoV-2

PURPOSE

To search for a clinical potential link between subacute thyroiditis (SAT) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a series of patients diagnosed with SAT during the COVID-19 pandemic, by retrospective evaluation of (1) clinical symptoms and (2) contact tracing.

METHODS

SAT  patients diagnosed from March to December 2020 were enrolled. The presence of typical clinical presentation of SARS-CoV-2, diagnostic tests for SARS-CoV-2, and contact with other individuals proven to be positive for SARS-CoV-2 were searched.

RESULTS

Ten SAT  cases were included. Fever was recorded in four patients. Cough, dyspnea, and headache were rarely reported. No patient had diagnosis of pneumonia. Two patients had moderate to severe fatigue after SAT. One patient experienced loss of smell and taste and had persistent fatigue over the following five months. No patient had positive SARS-CoV-2 diagnostic tests. At contact-tracing evaluation, only one patient had a contact with people who were diagnosed with SARS-CoV-2.

CONCLUSIONS

Patients diagnosed with SAT during COVID-19 pandemic rarely experienced SARS-CoV-2-related symptomatology. The contact tracing did not show close contact with SARS-CoV-2 individuals in 9/10 cases.

The Importance of Vitamin D Level in Subacute Thyroiditis Disease and the Effect of Vitamin D on Disease Prognosis

OBJECTIVE

Subacute thyroiditis (SAT) is an inflammatory thyroid disease that manifests with severe pain. The presence of the vitamin D receptor in immune system cells shows that vitamin D deficiency can trigger inflammatory diseases. The aim of the present study was to determine the prevalence of vitamin D deficiency in SAT patients, and the relationship between vitamin D level and permanent hypothyroidism and recurrence rate.

METHODS

In this retrospective study, 25-hydroxyvitamin D (25[OH]D) levels of 170 SAT patients and 86 control subjects were compared.

RESULTS

The 25(OH)D levels were significantly lower in the SAT patients, and there was no seasonal difference. A negative correlation was determined between the erythrocyte sedimentation rate and 25(OH)D, but no significant relationship was found between vitamin D level and prognosis.

CONCLUSION

As a result of this study, it was shown that vitamin D levels in subacute thyroiditis patients were significantly lower than in the healthy control group. Although there is no relationship between vitamin D level and disease prognosis, vitamin D deficiency may increase the rate of respiratory tract infections (especially, influenza, coxsackievirus, measles, adenovirus, retroviruses) and eventually SAT development.

Subacute Thyroiditis After Sars-COV-2 Infection

CONTEXT

Subacute thyroiditis (SAT) is a thyroid disease of viral or postviral origin. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that began in Wuhan, China, has spread rapidly worldwide and Italy has been severely affected by this outbreak.

OBJECTIVES

The objective of this work is to report the first case of SAT related to SARS-CoV-2 infection.

METHODS

We describe the clinical, laboratory, and imaging features of an 18-year-old woman who came to our attention for fever, neck pain radiated to the jaw, and palpitations occurring 15 days after a SARS-CoV-2-positive oropharyngeal swab. Coronavirus disease 2019 (COVID-19) had been mild and the patient had completely recovered in a few days.

RESULTS

At physical examination the patient presented with a slightly increased heart rate and a painful and enlarged thyroid on palpation. At laboratory exams free thyroxine and free triiodothyronine were high, thyrotropin undetectable, and inflammatory markers and white blood cell count elevated. Bilateral and diffuse hypoechoic areas were detected at neck ultrasound. One month earlier, thyroid function and imaging both were normal. We diagnosed SAT and the patient started prednisone. Neck pain and fever recovered within 2 days and the remaining symptoms within 1 week. Thyroid function and inflammatory markers normalized in 40 days.

CONCLUSIONS

We report the first case of SAT after a SARS-CoV-2 infection. We alert clinicians to additional and unreported clinical manifestations associated with COVID-19.

Establishing a diagnostic scale of subacute thyroiditis without radioisotope scanning

BACKGROUND

Radioisotope scanning is important to diagnose subacute thyroiditis (SAT), but it's not always available. So we aim to establish a diagnostic scale for SAT without radioisotope scanning.

METHODS

The suspected SAT patients hospitalized in Yuebei people's Hospital from January 2012 to December 2016 were selected and divided into study group and control group according to whether they were diagnosed as SAT. The clinical indexes of two groups were collected and the diagnostic scale of SAT was established by using binary logistic regression analysis. The effectiveness of the scale was evaluated by ROC curve.

RESULTS

Of 309 patients, 58.25% of patients were confirmed with SAT and the remaining 41.75% of patients were not diagnosed with SAT. After univariate analysis, variables which were considered statistically different(P < 0. 05) between the two groups were selected as independent variables and the diagnosis of SAT was taken as dependent variable in the binary logistic regression model. The logistic regression model consisted of 4 variables, each was thyroid tenderness, firm on palpation, increased ESR and elevated thyroid hormone level. The P value of Omnibus tests was≤0. 001 and the Nagelkerke R Square was 0. 915. The diagnostic scoring scale was established with these four variables according to their regression coefficient. The area under the ROC curve for this diagnostic scale was 0. 991(95% confidence interval, 0. 982-0.999). The highest Youden index was 0. 912, the corresponding cut-off point was 7. Internally validation shows a sensitivity of 92. 78% and a specificity of 98.45% of our scale.

CONCLUSIONS

We established and validated a diagnostic scale for SAT without the need for radioisotope scanning for the first time. It has good application in institutions that do not have radioisotope machines or among pregnant and lactating women.

Subacute Thyroiditis – An Underestimated Diagnosis: Description of a Case Series

Subacute thyroiditis is a relatively rare thyroid disease that develops after acute viral upper respiratory tract infection and manifests with neck pain, fever and transient hyperthyroidism. The diagnosis is often delayed due to the non-specific presentation and laboratory findings. It is misdiagnosed with upper respiratory tract infections, cervical lymph-adenitis, even with acute pyelonephritis. The authors present a series of 12 patients with subacute thyroiditis and discuss the main steps in the diagnosis, differential diagnosis and treatment of this disease.

Hemogram parameters in the patients with subacute thyroiditis

Background &Objective

Subacute Granulomatous Thyroiditis (De Quervain's Thyroiditis) is an acute painful inflammatory disease of the thyroid. We aimed to investigate easily accessible and cheap hemogram based parameters of Neutrophil to Lymphocyte Ratio (NLR), Platelet to Lymphocyte Ratio (PLR), and Mean Platelet Volume (MPV) in the follow up of inflammatory thyroid disease.

Methods

Patients admitted to Sakarya University Education and Research Hospital Endocrinology and Metabolism Outpatient Clinic and diagnosed as Subacute Granulomatous Thyroiditis between May 2017 and November 2018 were included in the study. Hemogram, thyroid function tests and acute phase values of these patients were recorded and compared with the values after treatment and disease recovery. On the sixth month, thyroid function tests were repeated and the rate of permanent hypothyroidism was screened. The relationships between initial hemogram parameters and acute phase reactants were evaluated.

Results

Total 71 patients were included in our study. 60 (84.5%) were female and 11 (15.5%) were male. The F/M ratio was found to be 6/1. Mean age was 43 ± 9.95 years. Receiver Operating Characteristics (ROC) Curve Analysis was performed and values for Area Under the Curve (AUC) for NLR and PLR, respectively, were 0.739 (95% CI 0.657-0.820 p<0.0001) and 0.772 (95% CI 0.694-0.850 p<0.0001), which are significant and associated with disease activity. However, the AUC for MPV parameter was: 0.578 (95% CI 0.484-0.672 P_: 0.10) and was not significant. The cut off values defined as 2.4 (80% sensitivity and 51% specificity) for NLR and 146.84 (83% sensitivity and 54% specificity) for PLR for the acute phase of the disease. In the Correlation Analysis, NLR and PLR values were significantly correlated with ESR and CRP parameters, which are the most commonly used acute phase reactants.

Conclusion

According to the present study, we believe that the NLR and PLR parameters will be of benefit in the follow-up the disease, accurately demonstrate the inflammatory load in the acute phase of the disease, and correlate with the common acute phase reactants.

Is There Seasonality in Hypothyroidism? A Google Trends Pilot Study

INTRODUCTION

There may be seasonality in thyroid diseases and internet search data may provide information on disease patterns. In this study we used data from internet searches on hypothyroidism to assess seasonality in this disease.

METHODS

We collected worldwide data, as well as data for countries in the southern hemisphere (Brazil, South Africa, and Australia), covering 15 years, from Google Trends with the search term "hypothyroidism+thyroiditis (the commonest cause of hypothyroidism)" and "fatigue+weakness (the commonest symptoms of hypothyroidism)". We looked for periodicity in relevant internet searches by calculating autocorrelations; we also looked at the cross-correlation of internet searches for "hypothyroidism+thyroiditis" and "fatigue+weakness" and we compared the results by season with the Kruskall-Wallis test.

RESULTS

There was periodicity in the relevant internet searches and strong cross-correlations between internet searches for "hypothyroidism+thyroiditis" and "fatigue+weakness" worldwide and for South Africa and Australia. In both the northern and the southern hemispheres there were significantly more hypothyroidism-related internet searches during spring (p<0.05).

CONCLUSION

Hypothyroidism was more popular in internet searches at springtime in the northern and the southern hemispheres. Thus, although this analysis is coarse, it seems that some seasonality can be inferred on hypothyroidism, taking into account the limitations of our approach.

Fever of Unknown Origin as a Sole Presentation of Subacute Thyroiditis in an Elderly Patient: A Case Report with Literature Review

An 80-year-old Caucasian male presented with fever of 3-week duration. Outpatient workup for infectious etiologies was negative and due to persistent fever, he was hospitalized for further evaluation of fever of unknown origin (FUO). Physical examination and laboratory studies remained unremarkable; however a follow-up CT scan of chest, abdomen, and pelvis with contrast done to rule out malignancy as an underlying cause of FUO revealed heterogeneous thyroid gland with surrounding hazy changes suggestive of thyroiditis. Thyroid function tests confirmed the diagnosis of subacute thyroiditis. The patient was started on prednisone with good response in his symptoms and was eventually discharged to home. The importance of our case lies in the fact that diagnosing subacute thyroiditis in the absence of classical symptoms of neck pain can be challenging and a physician should have a very high index of suspicion especially in an elderly patient where FUO can be the sole presentation.

Cytomorphological Spectrum of Thyroiditis: A Review of 110 Cases

Introduction

Different types of thyroiditis may share some parallel clinical and biochemical features. Timely intervention can significantly reduce morbidity and mortality.

Aim

Aim of this study is to find the frequency of various thyroiditis, study the cytomorphological features and correlate with clinical findings including radiological findings, thyroid function test, and anti-thyroid peroxidase antibodies (Anti-TPO antibodies).

Materials and Methods

The study included consecutive 110 cases of thyroiditis. Detailed cytomorphological features were studied and correlated with ultrasonography findings, thyroid function test, anti-thyroid peroxidase antibodies (anti-TPO) and histopathological features where thyroidectomy specimens were received for histopathological examination.

Results

The majority were Hashimoto's thyroiditis (n = 100) and females (n = 103). Other forms of thyroiditis were Hashimoto's thyroiditis with colloid goiter (n = 5), De Quervain's thyroiditis (n = 3), and one case each of postpartum thyroiditis and Hashimoto's thyroiditis with associated malignancy. The majority of patients were in the age group of 21-40 (n = 70) and the majority (n = 73) had diffuse enlargement of thyroid. The majority of patients were hypothyroid (n = 52). The serum anti-TPO antibodies were elevated in 47 patients out of 71 patients. In the 48 patients who underwent ultrasonography, 38 were diagnosed as having thyroiditis. The most consistent cytomorphological features seen in fine-needle aspiration smears of Hashimoto's thyroiditis were increased background lymphocytes, lymphocytic infiltration of thyroid follicular cell clusters, and Hurthle cells.

Conclusion

The diagnostic cytological features in Hashimoto's thyroiditis are increased background lymphocytes, lymphocytic infiltration of thyroid follicular cell clusters, and Hurthle cells. FNAC remains the "Gold Standard" for diagnosing Hashimoto's thyroiditis. Clinical history, thyroid function, and biochemical parameters are the key for diagnosis of other forms of thyroiditis.

Treatment of Acute Painful Thyroiditis with Low Dose Prednisolone: A Study on Patients from Western Nepal

INTRODUCTION

Thyroiditis is a disorder that involves inflammation of the thyroid gland. Subacute thyroiditis is the most common cause of acute painful thyroiditis. It is thought to be a viral inflammatory disorder. Subacute thyroiditis has been treated with either nonsteroidal anti-inflammatory drugs (NSAIDs) or high dose corticosteroids. The response to steroids is more dramatic and quicker than the NSAIDs. Prednisolone is the most commonly used corticosteroid to treat subacute thyroiditis. The usual dose is one mg/kg/day tapered over six weeks although the basis for this dose has not been established yet by prospective studies.

AIM

The current research was carried out to study if prednisolone in lower initial dose (20 mg/day tapered over four weeks) is effective in patients with acute painful thyroiditis.

MATERIALS AND METHODS

This study was a prospective, cross sectional, observational study carried out at Pokhara, Nepal. All the patients presenting with anterior neck pain of less than 1 week with tender thyroid on palpation and ESR more than 30mm/h were included in the study. The patients were administered prednisolone in a starting dose of 20 mg/day tapered over four weeks. Data were collected, analysed and the results were interpreted.

RESULTS

One hundred and twenty two patients of acute painful thyroiditis were included in our study. Age of the patients ranged from 19 years to 69 years with the mean age of 36.58 years. Female to Male ratio was 10:1. Mean ESR was 57.03 at the time of presentation. ESR decreased to 29.63 at two weeks and 17.03 mm per hour (normal) at 4 weeks after continuation of the drug. All the patients reported with severe pain in the anterior neck at the time of presentation. Pain was completely relieved in 115 patients (94%) at 2 weeks after starting the treatment and it was better than previous in seven patients.

CONCLUSION

Twenty mg of prednisolone daily tapered over 4 weeks is an adequate treatment of subacute thyroiditis. However, dose can be drastically tapered after 2 weeks.

Demographic data of thyroiditis from a south Indian city

BACKGROUND

Thyroiditis involves thyroid gland inflammation due to a wide variety of causes. The common varieties are subacute, silent and postpartum thyroiditis.

AIMS AND OBJECTIVES

To retrospectively collect demographic data of thyroiditis from Bangalore over the past 5 years.

MATERIALS AND METHODS

Data were collected from three major nuclear medicine centers in Bangalore of the patients who came for technetium (Tc) 99m pertechnetate scan of the thyroid. The diagnosis was based on the Tc 99 scan evidence of thyroiditis in these patients and biochemical evidence of thyrotoxicosis.

RESULTS

The total number of cases recorded were 2513. The females were more commonly affected compared with males with sex distribution of 1698 females and 815 females (2:1). The mean age of females was 32.5 ± 11.3 years whereas the mean age of males was 37.2 ± 12.4 years. The highest numbers of cases were recorded in the months of June and August.

CONCLUSIONS

The females developed thyroiditis frequently and at an earlier age when compared with males. This data could give us an insight into the demographic pattern of thyroiditis in our country and may help in planning future preventive strategies.

Chinese herbal medicine for subacute thyroiditis: a systematic review of randomized controlled trials

OBJECTIVE

To evaluate the effectiveness and safety of Chinese herbal medicine (CHM) in the treatment of subacute thyroiditis.

METHODS

Randomized controlled trials found in PubMed, Cochrane Library, and three Chinese databases were selected. RevMan 5.2 software was used to analyze the data with relative risk or mean difference, expressed with 95% of confidence interval. The quality of trials was assessed and graded the quality of evidence with GRADE profiler software.

RESULTS

Twenty one studies were included. CHM was superior to Western Medicine (include prednisone and NSAIDs) in abating fever, relieving thyroid pain, recovering blood sedimentation, improving thyroid function, and preventing hypothyroidism (P < 0.05), while no statistical differences were found in eliminating goiter and reducing relapse rate. CHM plus Western Medicine were superior to Western Medicine in abating fever, relieving thyroid pain, eliminating goiter, and reducing relapse rate, while no statistical differences (P > 0.05) were found in recovering blood sedimentation and improving thyroid function. The incidence of adverse reactions in treatment group was lower than that in control group (relative risk was 0.12 and 95% confidence interval was 0.03-0.51). The methodological quality of trials is generally poor with a high risk of bias.

CONCLUSION

CHM (particularly CHM combined with Western Medicine) used to treat subacute thyroiditis may improve clinical symptoms and signs, reduce relapse rate, and alleviate the side effects of hormones. Due to poor methodological quality of included trials, further more high-quality studies are warranted to confirm the effectiveness and safety of CHM.

Thyroglobulin autoantibodies of patients with subacute thyroiditis are restricted to a major B cell epitope

BACKGROUND

Thyroglobulin autoantibodies (TgAb) can develop in patients with subacute thyroiditis (SAT).

AIM

Comparison of the epitope pattern of TgAb of patients with SAT, Hashimoto's thyroiditis (HT) [autoimmune thyroid disease (AITD)] and non-toxic multinodular goiter (NTMG) (non-AITD).

SUBJECTS AND METHODS

Serum TgAb from 10 patients with SAT, 45 with HT, and 19 with NTMG were evaluated. Serum TgAb binding to Tg was inhibited by 4 recombinant human TgAb-Fab, recognizing Tg epitope regions A, B, C, and D. The ability of single TgAb-Fab to inhibit the binding of serum TgAb to Tg was evaluated in enzymelinked immunosorbent assay.

RESULTS

Levels of inhibition were different for all TgAb-Fab in the 3 groups of patients. Inhibition by region A TgAb-Fab in SAT [50.5 (30.3-62.5)%] (median and 25th to 75th percentiles) was similar to HT [49.0 (38.0-69.5)%] and significantly higher than in NTMG [25.0 (14.0-37.0)%]; by region B TgAb-Fab in SAT [0.0 (0.0-12.5)%] was significantly lower than in HT [28.0 (9.5-48.0)%] and similar to NTMG [9.0 (4.8-20.5)%]; by region C TgAb-Fab in SAT [9.5 (0.0-25.8)%] were similar to HT [23.0 (9.5-41)%] and NTMG [6.5 (1.7-21.5)%]; and by region D TgAb-Fab in SAT [0.0 (0.0-8.0)%] were lower than in HT [12.0 (1.0-28.5)%] and similar to NTMG [1.0 (0.0-5.0)%].

CONCLUSIONS

The epitope pattern of TgAb of SAT is restricted to the A region that is immunodominant in AITD and non-AITD. In the majority of patients with SAT, the autoimmune phenomena represent a non-specific and transient response to the release of thyroid antigens, rather than the expression of thyroid autoimmunity.

Eponym : de Quervain thyroiditis

de Quervain thyroiditis is a self-limited inflammatory disorder of the thyroid gland. It is an uncommon disease in adults and very rare in children. Fritz de Quervain, a Swiss surgeon, who was an authority on thyroid disease, described the unique pathology of this disease. Granulomatous changes with giant cells in thyroid tissue are the pathological findings. Viral infection in genetically predisposed individuals has been proposed as the pathogenesis of the disease. Clinical hallmarks for the diagnosis are painful thyroid enlargement, elevated erythrocyte sedimentation rate, and C-reactive protein as well as decreased uptake of the thyroid gland on thyroid scintigraphy. In addition, thyrotoxicosis is present in about 50% of cases in early phase of the disease. Serum thyroglobulin level is usually elevated. Only symptomatic treatment with analgesics is usually required for pain relief. Glucocorticoid therapy may be used in severely ill patients. de Quervain thyroiditis is generally completely resolved without complications in 6-12 months. However, permanent hypothyroidism and recurrent disease have been reported in some patients.

Viruses and thyroiditis: an update

Viral infections are frequently cited as a major environmental factor involved in subacute thyroiditis and autoimmune thyroid diseases This review examines the data related to the role of viruses in the development of thyroiditis.

Our research has been focused on human data. We have reviewed virological data for each type of thyroiditis at different levels of evidence; epidemiological data, serological data or research on circulating viruses, direct evidence of thyroid tissue infection. Interpretation of epidemiological and serological data must be cautious as they don't prove that this pathogen is responsible for the disease. However, direct evidence of the presence of viruses or their components in the organ are available for retroviruses (HFV) and mumps in subacute thyroiditis, for retroviruses (HTLV-1, HFV, HIV and SV40) in Graves's disease and for HTLV-1, enterovirus, rubella, mumps virus, HSV, EBV and parvovirus in Hashimoto's thyroiditis. However, it remains to determine whether they are responsible for thyroid diseases or whether they are just innocent bystanders. Further studies are needed to clarify the relationship between viruses and thyroid diseases, in order to develop new strategies for prevention and/or treatment.

Clinical characteristics of 852 patients with subacute thyroiditis before treatment

OBJECTIVE

Subacute thyroiditis (SAT) is a transient inflammatory disease of the thyroid. We evaluated the clinical characteristics based on laboratory and imaging studies in patients with SAT before treatment.

PATIENTS

We reviewed the medical records of 852 patients (107 men and 745 women) with SAT who visited our thyroid clinic at Kuma Hospital from 1996 through 2004.

RESULTS

SAT developed most often in female patients aged 40 to 50 years, with significant seasonal clusters during summer to early autumn. While the rates of any virus infections and diseases did not differ from those in the general population, recurrent episodes of SAT at intervals of 13.6+/-5.6 years accounted for 1.6% of all cases. At the onset of SAT, 28.2% of patients had temperatures greater than 38 degrees C and typical symptoms associated with thyrotoxicosis developed in more than 60% of patients. Before treatment, most of the abnormal laboratory findings associated with thyrotoxicosis, inflammation, and liver dysfunction reached peak levels within 1 week after onset. Ultrasound examination showed that half of the patients with unilateral thyroid pain presented with bilateral hypoechogenic area in the thyroid and the rate of bilateral hypoechogenic area tended to increase 2 months after onset.

CONCLUSION

Laboratory studies of thyroid dysfunction and inflammation related to SAT presented peak levels within 1 week after onset.

Subacute thyroiditis: clinical characteristics and treatment outcome in fifty-six consecutive patients diagnosed between 1999 and 2005

OBJECTIVE

To identify predictive factors of clinical outcome of subacute thyroiditis.

DESIGN

Retrospective case series of 56 consecutive patients treated in 3 outpatient clinics between 1999 and 2005. Medical records were reviewed for demographic data, seasonal disease distribution, laboratory and clinical course, treatment, and short-term outcome.

MAIN OUTCOME

Mean age was 48.6+/-12 yr; 70% were females. Twenty-five percent had antithyroid antibodies and 9% had recurrent disease. Differences in occurrence by season were not significant (p=0.28). Ultrasound, performed in 35 patients, revealed thyroid nodules in 25 (median size, 17 mm). Ten patients received no treatment, and 43 received either non-steroidal anti-inflammatory drugs (NSAID) (no.=25) or glucocorticoids (no.=18); data for 3 patients were missing. Median disease duration was 77 days; mean peak free T4 (FT4) level was 43.7+/-25.3 pmol/l. A hypothyroid phase was documented in 31 patients, and remained permanent in 6. Peak FT4 level, but not erythrocyte sedimentation rate or clinical score, was positively correlated with the highest TSH level and with disease duration. Untreated patients had less severe clinical disease than treated patients, but a similar outcome. Patients given glucocorticoids had a shorter overall disease duration (p=0.03), with no differences in duration of hyperthyroidism, peak FT4 or highest TSH levels, compared with patients given NSAID.

CONCLUSION

Subacute thyroiditis follows an unpredictable clinical course that is hardly affected by its clinical features or treatment.

Hyperthyroidism

Thyrotoxicosis is a condition resulting from elevated levels of thyroid hormone. In this article, the authors review the presentation, diagnosis, and management of various causes of thyrotoxicosis.

Demographic and clinical features of patients with subacute thyroiditis: results of 169 patients from a single university center in Turkey

BACKGROUND

Turkey is an endemic area for thyroid diseases. The Aegean region is well documented for increased prevalence of thyroid disorders. In this study we investigated the demographic and clinical features of subacute thyroiditis (SAT) patients who had been diagnosed and treated in Ege University.

METHODS

The hospital files of patients admitted to the endocrinology clinic of Ege University between January 1987 and December 2001 were retrospectively evaluated. Patients who had been diagnosed as having any thyroid disorder were determined.

RESULTS

176 fulfilled diagnostic criteria for SAT. The majority of patients with SAT were diagnosed as having subacute granulomatous thyroiditis (169/176) (134 females, 35 males, mean age 34.0+/-17.8 yr); 69% of the patients were between 30-50 yr of age. Thyroid pain was present in 97.1% of female patients, and in 100% of male patients. High fever was evident in 78 patients (46.2%). Mean erythrocyte sedimentation rate (ESR) was 43.42+/-39.68 mm/h. Anti-thyroglobulin antibody was positive in 20%, and anti-thyroid peroxydase antibody was positive in 4% of patients. Among patients who were treated with non-steroidal anti-inflammatory drugs (NSAD) 10 female patients (10.6%), and 3 male patients (12%) developed recurrence of the disease. Among patients who were treated with prednisolone 7 female patients (17.5%), and one male patient (10%) developed recurrence. There was no significant difference regarding the recurrence rates between patients who were treated with NSAD and patients who were treated with prednisolone.

CONCLUSION

With the exception of ESR, demographic, clinical, laboratory, and imaging findings and prognoses of our patients were comparable to the previous reports.

Subacute thyroiditis developed in identical twins two years apart

A 34-year-old woman was referred to our hospital complaining of sore throat and arthralgia. She had low-grade fever, tachycardia, and goiter with tenderness. Laboratory data revealed thyrotoxicosis and tests for acute inflammatory markers were positive. Thyroidal radioactive iodine uptake was below normal. Ultrasonography of thyroid revealed mild thyroid enlargement and hypoechogenic areas consistent with tenderness. Subacute thyroiditis was diagnosed and prednisone was administered. Two years later, her identical twin sister, who lives separately, was referred to our hospital because of neck pain, low-grade fever, and palpitation. She exhibited the same clinical picture as her twin sister, and was also diagnosed as having subacute thyroiditis. Although the cause of subacute thyroiditis remains unclear, viral infection has been implicated in the onset of subacute thyroiditis in genetically predisposed individuals. We could not identify the viruses, but heterozygotes for HLA-B35, which has been reported to be linked with subacute thyroiditis, were found in the twins. This supports the suspicion that genetic factors, including this HLA haplotype, play a critical role in the onset of subacute thyroiditis.

[Pharyngitis, massive ESR elevation and hyperthyroidism in a 71-year-old female patient]

We present a 71-year-old female patient suffering from a sore throat with unilateral neck swelling, pain on swallowing, subfebrile temperatures and general fatigue persisting for several weeks without any clinical signs of hyperthyroidism, although laboratory findings show high concentrations of T(3) and T(4) and a low TSH. A massive ESR elevation is found as well. Ultrasound reveals an inhomogeneous pattern of the thyroid gland with low echogenicity. (99m)Tc pertechnetate uptake is suppressed. The diagnosis of acute/subacute thyroiditis de Quervain is concluded. Therapeutic application of prednisone leads to a swift improvement, yet two weeks later asymptomatic hypothyroidism is diagnosed, requiring substitution of thyroxine. We discuss de Quervain's thyroiditis and the differential diagnosis of inflammatory disorders of the thyroid gland.

Subacute thyroiditis: Fine-needle aspiration cytology of 14 cases presenting with thyroid nodules

Subacute thyroiditis (SAT) is usually diagnosed clinically without the need for fine-needle aspiration. The cytologic literature on this condition is therefore rare. We report on 14 cases of SAT presenting with thyroid nodules. The majority of patients were women with a mean age of 46 yr. All had pain/tenderness in the thyroid area accompanied by fever or an elevated ESR. The salient cytologic features included cellular smears; multinucleated giant cells in 100% of cases, some ingesting colloid or neutrophils; fibrous fragments with enmeshed inflammatory cells were a constant feature; follicular cells were scant to absent in most cases. Granulomas were rare. Colloid, when present was thick, with central cracks and frayed edges. One case was suspicious for malignancy. We conclude that the cytologic features of SAT are predictable, particularly, in the appropriate clinical setting. FNA is also helpful in ruling out concomitant neoplastic conditions.

Clinical features and outcome of subacute thyroiditis in an incidence cohort: Olmsted County, Minnesota, study

Subacute thyroiditis (SAT), or granulomatous thyroiditis, is an inflammatory thyroid condition associated with pain and systemic symptoms. Few community studies are available. We studied the 160 patients with SAT in Olmsted County, Minnesota, seen between January 1, 1960, and December 30, 1997. Subjects were identified through the medical diagnostic index of the Rochester Epidemiology Project. The overall age- and sex-adjusted incidence from 1960 through 1997 was 4.9 cases per 100,000/yr. In the most recent 28-yr period (1970-1997), 94 patients were identified. In this group, pain was the presenting symptom in 96%. SAT recurred in 4% of the patients 6-21 yr after the initial episode. Corticosteroid therapy was given to 36%. Early-onset hypothyroidism occurred both in patients receiving corticosteroid therapy (29%) and in those not receiving corticosteroid therapy (37%). At latest follow-up, significantly more patients who had received corticosteroid therapy had a diagnosis of hypothyroidism than the group without corticosteroid therapy (25% vs. 10%, P < 0.05; overall rate of hypothyroidism, 15%). Early transient hypothyroidism is common in SAT. Permanent hypothyroidism is less common, and only 15% of the patients are receiving T(4) therapy after 28 yr of follow-up. Symptomatic relief is achieved with corticosteroid therapy, but such therapy does not prevent early- and late-onset thyroid dysfunction.

Familial occurrence of subacute thyroiditis

Although subacute thyroiditis (de Quervain's thyroiditis) is presumed to be caused by a viral infection, only 2 familial occurrences of subacute thyroiditis have been reported in the literature. Typical and severe subacute thyroiditis was diagnosed in an older sister who was hospitalized for 8 days. During this period her younger sister nursed her. Three weeks after, the same clinical picture occurred in the younger sister. We postulate that subacute thyroiditis might occur by transmission of possible viral infection in genetically predisposed individuals.

Subacute thyroiditis in an immunosuppressed patient

Subacute thyroiditis is a well-recognized cause of transient thyrotoxicosis, resulting from a destruction injury to the thyroid. The pathogenesis of this condition is not completely understood and there is debate regarding the extent of the contribution of autoimmunity and external agents, such as infections, to this process. We present the first reported case of subacute thyroiditis in a patient who had been on chronic lithium therapy as well as long-term immunosuppression, with cyclosporin and prednisolone, following an allogeneic bone marrow transplant. We speculate that this case suggests a minimal role of autoimmunity in the development of subacute thyroiditis.

Atypical subacute thyroiditis: preliminary observations

Nine patients with painless or minimally painful subacute thyroiditis were seen between late June and October 2000. Six had a history of antecedant viral symptoms. Thyroid peroxidase antibodies were negative in eight patients tested; none had a family history of autoimmune thyroid disease. It is possible that these patients represent examples of postviral painless subacute thyroiditis (atypical subacute thyroiditis). In order to establish the nature of the syndrome, cytological examination, HLA typing, and long-term follow-up are necessary.

Evaluation of infectious etiology in subacute thyroiditis--lack of association with coxsackievirus infection

The etiology of subacute granulomatous thyroiditis (SAT) is obscure, although it is postulated to be associated with viral infections and genetic factors. In the present study, the possibility of an infectious etiology was prospectively studied in 27 consecutive patients with SAT. Special emphasis was put on the role of enteroviruses. Coupled sera (interval one month) were taken from all patients and single sera from 29 control subjects for virus antibody determinations. Stool samples were collected for virus isolation and fine-needle aspiration samples from thyroid gland for the detection of enterovirus RNA using RT-PCR were taken from SAT patients. Enteroviral antibodies were tested using three different methods: indirect EIA, heavy chain capture RIA, and standard complement fixation (CF) test. Antibodies against other common viral pathogens, including enteroviruses, were screened using the CF test and those against Mycoplasma pneumoniae and Chlamydia pneumoniae using EIA and microimmunofluorescence techniques, respectively. Common respiratory viruses were also screened from nasopharyngeal suction samples by antigen detection EIA. Based on serological findings, one patient had acute Cytomegalovirus infection. All other patients were negative in antibody tests, virus isolation, RT-PCR, and antigen detection. Enterovirus RNA was not detected by PCR in the thyroid tissue in any of the fine-needle aspiration samples. There was no evidence of recent enteroviral infections in SAT patients. The results suggest that SAT is not usually associated with acute infections. No evidence was obtained to support the proposed role of enteroviruses as an important etiologic agent of SAT.

Syndromes of thyrotoxicosis with low radioactive iodine uptake

It is very important to diagnose correctly the etiology of thyrotoxicosis, because the course and treatment of thyrotoxicosis with low radioactive iodine uptake differ significantly from that of hyperthyroidism due to Graves' disease or toxic nodular goiter. Many causes of subacute thyroiditis have been identified producing a characteristic course of transient hyperthyroidism, followed by hypothyroidism, and usually recovery. Ectopic hyperthyroidism includes factitious thyroid hormone ingestion, struma ovarii, and, rarely, large deposits of functioning thyroid cancer metastases. Iodine-induced hyperthyroidism may be associated with low radioiodine uptakes. Amiodarone-associated hyperthyroidism may be the result of subacute thyroiditis or iodine-induced hyperthyroidism; assessment and treatment can be quite challenging.