The management of subacute (DeQuervain's) thyroiditis

The role of severity and duration of inflammation and hematological parameters on the outcome of subacute thyroiditis

Background: The role of severity and duration of inflammatory findings on the development of persistent hypothyroidism and anemia has not been clarified in subacute thyroiditis (SAT). Methods: Demographic data and laboratory parameters of patients with SAT were analyzed retrospectively. Results: Permanent hypothyroidism was observed in 28.1% of patients. Baseline elevated erythrocyte sedimentation rate as defined >74.5 mm/h was found to be associated with permanent hypothyroidism, but the duration of inflammation was not different between the recovered and hypothyroid patients. Baseline hemoglobin values improved without specific therapy in 3.5 months. Conclusion: The initial severity but not the duration of inflammation increases the risk for the development of permanent thyroid dysfunction, and anemia improves with the resolution of inflammation.

Comparison of the therapeutic effects of 15 mg and 30 mg initial daily prednisolone doses in patients with subacute thyroiditis: a multicenter, randomized, open-label, parallel-controlled trial

INTRODUCTION

Current guidelines recommendations for the initial dose of prednisolone (PSL) in the treatment of subacute thyroiditis (SAT) are based on low-quality studies. We designed a randomized controlled trial (RCT) to compare the efficacy and safety of using a low initial dose of PSL with a standard initial dose of PSL in SAT patients.

PATIENTS AND METHODS

This open-label RCT was conducted at five hospitals in China from June 2019 to January 2022. SAT patients with moderate-to-severe pain or a poor response to non-steroidal anti-inflammatory drugs (NSAIDs) were randomly assigned in a 1:1 ratio to the experimental and control groups. The initial dose of PSL was 15 mg/d in the experimental group and 30 mg/d in the control group. The primary outcome was the total duration of PSL treatment, with non-inferiority prespecified with a margin of 7 days. Clinical trial registration number: ChiCTR1900023884.

RESULTS

The full analysis set included 60 patients (30 in each group). The mean duration of PSL treatment in the experimental and control group was 34.62 ± 14.12 and 41.18 ± 16.89 days, respectively, meeting the non-inferiority criterion (pnon-inferiority = 0.0006). The total dose of PSL used in the experimental group was lower than in the control groups (330 vs 595 mg, p < 0.0001). There were no differences in the mean time to pain relief and complete resolution, the occurrence of recurrence, hypothyroidism, or adverse events between the groups.

CONCLUSIONS

The initial dose of 15 mg/d of PSL was not inferior to the dose of 30 mg/d in terms of efficacy and showed a similar safety profile. A low initial dose of PSL could be recommended for Chinese adult SAT patients who have a suboptimal response using NSAIDs or experience moderate-to-severe pain.KEY MESSAGESLow initial dose (15 mg/d) of prednisolone was non-inferior to the standard initial dose of prednisolone (30 mg/d) in treatment duration, time to pain relief, or the prevalence of hypothyroidism, recurrence, and adverse reactions in the treatment of subacute thyroiditis.Patients with subacute thyroiditis administered a low initial dose of prednisolone had a lower total dose of prednisolone compared to those receiving the standard dose of prednisolone.

Clinical Aspects in Subacute Thyroiditis: A Real-Life Study on 226 Cases in Greece Amid the COVID-19 Pandemic

PURPOSE

This study aimed to evaluate various therapeutic approaches, identify potential predictive factors for the recurrence and development of hypothyroidism, and examine specific clinical and laboratory characteristics of patients with subacute thyroiditis (SAT) due to SARS-CoV-2 infection.

METHODS

We retrospectively analyzed the medical records of 226 patients with confirmed SAT diagnosed from January 2020 to November 2022.

RESULTS

The mean age was 48.01 ± 0.75 years, and the F/M ratio was 2.3/1. At the end of the follow-up period, 69 patients (32.1%) had developed hypothyroidism. Treatment duration was significantly shorter with nonsteroidal anti-inflammatory drugs (NSAIDs) (17.40 ± 2.56 days), while time-to-symptom relief was shorter with glucocorticoids (CGs). Recurrence was observed only in those treated with corticosteroid preparations (14.1%). C-reactive protein levels at treatment discontinuation were higher in patients who experienced SAT recurrence, while the coexistence of Hashimoto's thyroiditis was a significant predictive factor for the development of hypothyroidism. The TSH value at the time of treatment withdrawal >4.12 μIU/mL showed optimal sensitivity and specificity for the prediction of permanent hypothyroidism. Regarding COVID-19, 34 patients (15%) experienced related SAT, with similar clinical manifestations of the disease but a higher BMI and shorter time-to-symptom relief.

CONCLUSION

In conclusion, GCs administration alleviated acute symptoms earlier during the onset of SAT, whereas NSAIDs had a shorter treatment duration, and both regimens could not prevent the development of delayed hypothyroidism. The clinical characteristics of SAT due to COVID-19 infections were similar to those of typical SAT disease.

Subacute Thyroiditis Complicating COVID-19 Infection

Subacute thyroiditis (SAT) is a self-limited inflammatory disease and a rare cause of thyrotoxicosis. Although the exact etiology of SAT is not sufficiently understood, it is generally associated to viral infections. Current evidence highlights that SAT may be a potentially uncommon manifestation of ongoing Coronavirus disease 2019 (COVID-19) infection or a post-viral complication of the disease. Despite that SAT is a rare manifestation associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease both in ongoing and resolved COVID-19 infection, the ever-increasing numbers of COVID-19 patients strengthens the possibility that this particular disease entity will be of more immediate concern in the future. The current work aims to summarize the approach of SARS-CoV-2-associated SAT, present its pathophysiology, outline current research evidence found in the literature, and discuss potential differential diagnoses and diagnostic dilemmas through an illustrative case.

Management of Subacute Thyroiditis - A Systematic Review of Current Treatment Protocols

Purpose

This systematic review endeavors to find an effective treatment protocol for subacute thyroiditis (SAT) to minimize side effects, recurrence and long-term hypothyroidism.

Materials and Methods

We analyzed available original studies on treatment protocols for SAT. A thorough literature search was performed on the following online databases PubMed, Cochrane library nd Google Scholar using appropriate keywords for choosing relevant articles. Two reviewers assessed the methodological quality of selected articles independently using a critical appraisal instrument. The results were analyzed and synthesized qualitatively using the level of evidence method.

Results

The literature search retrieved a total of 460 publications after abstract screening; out of which 36 articles met the inclusion criteria. After full text screening, 23 articles were further excluded as they were focusing on aspects of SAT other than management, the remaining 15 articles were investigated for both reliability and validity. Thirteen studies provided low-quality evidence, and two randomized control trials (RCT) provided a high quality of evidence. Steroid therapy was found to be the most effective for moderate to severe SAT and provided relief from acute symptoms but was found to not be a risk factor for recurrence. Low initial doses of steroid (15 mg) were preferred over high initial dosage (30–40 mg). Furthermore, a look into the mode of steroid delivery (RCT) revealed that intrathyroidal steroid therapy can potentially become a safer and faster mode of therapy. The duration of tapering was found to be of significance as a short tapering period was linked with greater recurrence rates.

Conclusion

Low initial doses of steroid along with an extended tapering period may help lower recurrence rates; also, intrathyroidal steroid injections are potentially a better alternative to oral prednisone (PSN) with regard to safety and speed of action. However, the evidence is of moderate quality and further investigation is required.

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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.

Lessons of the month 1: A diagnostic dilemma: thyroid abscess or subacute thyroiditis?

Thyroid abscess is rare but potentially fatal, whereas subclinical thyroiditis is a self-limiting condition that is more commonly seen. The clinical features of both diseases can be overlapping but the treatment approach differs. We report a case of a painful left thyroid nodule not responding to conventional therapy for thyroiditis or thyroid abscess.

Factors affecting recurrence in subacute granulomatous thyroiditis

Objective

This study aimed to evaluate the factors affecting recurrence in subacute granulomatous thyroiditis (SAT).

Methods

A total of 137 patients with SAT were enrolled in the study; 98 (71.5%) were women and 39 (28.5%) were men. The patients received either steroid or nonsteroidal anti-inflammatory drug (NSAID) for eight weeks. Erythrocyte sedimentation rate (ESR), C-reactive protein, serum thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine (FT4), anti-thyroid peroxidase antibodies and thyroglobulin antibodies, neutrophil, lymphocyte, platelet, neutrophil to lymphocyte ratio, and platelet to lymphocyte ratio levels were evaluated. In addition, recurrence rates were compared between patients who received NSAID treatment and those who received steroid therapy.

Results

Treatment modality and pretreatment TSH, FT4, and ESR were significantly different between patients with and without recurrence (p = 0.011, 0.001, 0.004, and 0.026, respectively). Compared with patients without recurrence, those with recurrence had higher pretreatment TSH levels, but lower FT4 and ESR levels. On logistic regression analysis, treatment modality was found to be an independent risk factor for recurrence. The risk of recurrence was higher in those taking steroids than in those taking NSAIDs (p = 0.015). The optimal TSH cutoff value for recurrence was 0.045 µIU/mL, with a sensitivity of 83.3% and specificity of 76% (AUC 0.794, 95% CI 0.639-0.949).

Conclusion

The risk of SAT recurrence was higher with steroid therapy than with NSAIDs. Patients who had mild thyrotoxicosis had relatively high recurrence rate and may need a relatively longer duration of treatment.

Identifying the Lowest Effective Initial Dose of Prednisolone for the Treatment of Subacute Granulomatous Thyroiditis: A Systematic Review and Meta-Analysis

BACKGROUND

Subacute granulomatous thyroiditis (SAGT) is an inflammatory disease due to viral infections. Glucocorticoids, especially prednisolone (PSL), are one of the first approaches in the treatment of patients with SAGT. To date, no study has determined the lowest effective dose of prednisolone with the lowest recurrence rate in the treatment of SAGT. This study aimed to use meta-analysis methods to identify the appropriate dosage of prednisolone with the lowest recurrence rate in the treatment of patients with SAGT.

METHODS

This study was conducted according to the PRISMA checklist in February 2021. Two independent researchers performed a search for relevant literature published before March 2021 in English databases including Scopus, MEDLINE (via PubMed), Web of Science, Cochrane Library, Google Scholar, EMBASE, and also Persian electronic databases including SID, Iran medex, Magiran, and Irandoc. The search algorithm was initially developed by using a combination of MeSH terms, keywords, and also Boolean operators ("AND"; "OR"; "NOT"): Subacute thyroiditis, De Quervain Thyroiditis, Glucocorticoids, Prednisolone, Recurrence, and Meta-Analysis. All statistical analyses were performed using STATA 15.0 (StataCorp LLC, College Station, TX, USA) and SPSS 17.0. A random-effects model based on Metaprop were applied for the Meta-analysis. To assess heterogeneity between studies, the chi-squared test and I2 index were used, and for evaluating publication bias, funnel plots and Egger tests were performed.

RESULTS

The overall recurrence rate was 14.72% [95% CI: 9.63- 20.58] and there was a significant heterogeneity among the studies [I2 = 69.56%; P=0.000]. To evaluate the lowest effective dose of prednisolone, we divided the studies into two groups based on the mean initial dose of prednisolone: less than or equal to 20 mg/day (group one) and greater than 20 mg/day (group two). The recurrence rate in group 1 was 11% [95% CI: 5.7- 16.2] and in group 2 was 23.6% [95% CI: 11.5- 35.6]. Significant correlations were observed between the initial mean dose of PSL and recurrence rate (r= 0.71; P= 0.013). Begg's funnel plot there was no evidence of publication bias in these studies (p=0.160).

CONCLUSION

According to the results of this meta-analysis, 15 to 20 mg/day of prednisolone is the most effective dosage with the lowest recurrence rate in the treatment of subacute Granulomatous thyroiditis.

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.

Risk Factors for Subacute Thyroiditis Recurrence: A Systematic Review and Meta-Analysis of Cohort Studies

BACKGROUND

Subacute thyroiditis (SAT) is a self-limited inflammatory thyroid disease with recurring episodes. However, the results regarding the recurrence rate and risk factors for SAT are inconsistent. This meta-analysis aimed to summarize the evidence of the recurrence rate and the risk factors for SAT.

METHODS

The present study involved the performance of a systematic literature search of all English studies published in PubMed, Embase, Web of Science, and The Cochrane Library from inception to August 20, 2021. Cohort studies that reported the SAT recurrence rate and risk factors for recurrence were included. Two independent investigators extracted relevant information. Fixed- and random-effects models were used to pool effect sizes based on study heterogeneity.

RESULTS

Eighteen cohort studies were identified. The pooled findings showed that the recurrence rate was 12.0% (95% CI: 8.2%, 17.1%). The risk of recurrence in the glucocorticoids group was higher than that in the NSAIDs group (RR = 1.84, 95% CI: 1.04, 3.24). However, there was no significant difference in age or sex between the recurrence group and the non-recurrence group. Findings from one or two cohort studies also indicated that the copresence of HLA-B*18:01 and -B*35, the number of days required to taper prednisolone (PSL) to 5 mg/day, the duration of disease before treatment less than 30 days, the sialic acid level, or the TSH level at the termination of treatment and further extension of the hypoechoic area and increase in thyroid volume were related to the recurrence of SAT.

CONCLUSION

Recurrence was common in SAT patients. The present study indicated that glucocorticoid treatment was associated with a higher recurrence rate of SAT than NSAIDs treatment. The clinical implications of this association should be interpreted with caution, and further clinical trials on the long-term effects of different treatment strategies are needed.

Subacute thyroiditis with airway compromise in a 5-year-old boy

A 5-year-old boy presented with intermittent fever for 1 month, painful neck swelling associated with dysphagia, hoarseness of voice for 3 weeks and dyspnoea of 1-day duration. On evaluation, he had elevated serum thyroglobulin levels and inflammatory markers. There was a diffuse glandular thyroid enlargement with hypoechoic areas on neck ultrasonography. Fine-needle aspiration cytology was suggestive of subacute thyroiditis (SAT), and MRI of the neck confirmed narrowing of the trachea by the enlarged thyroid. He received steroids to relieve airway compression. Levothyroxine was started. On follow-up, he was symptom-free and euthyroid; steroids and levothyroxine were discontinued. SAT presenting with compression of trachea is rare in children. This highlights the need for identifying the type of thyroiditis to determine treatment modality.

Successful Management of Recurrent Subacute Thyroiditis by Adding Colchicine to Glucocorticoid Treatment: A Case Series Study

Although subacute thyroiditis (SAT) is thought to be a self-limited inflammatory thyroid disease, the recurrence rate of SAT is approximately 10-20%. It is difficult for these patients to stop glucocorticoid treatment, and they are usually bothered with recurrent pain and the side effects of glucocorticoids for more than several months. We describe three cases who were diagnosed with recurrent subacute thyroiditis after a reduction in prednisolone (PSL) dose, either immediately upon the cessation of PSL or shortly thereafter. Their symptoms, including the adverse effects of PSL, severely impacted their quality of life. After a complete assessment, we administered colchicine at 1 mg per day for 1-2 months to control the recurrence of SAT and monitored their routine blood parameters every two weeks. All 3 patients were successfully tapered off of PSL treatment and were free of frequently recurrent SAT. Colchicine may be therapeutic in patients with prednisolone-refractory, recurrent SAT. However, a large-scale, double-blind, controlled, prospective multicenter study is required to provide a solid body of evidence.

Initial treatment combined with Prunella vulgaris reduced prednisolone consumption for patients with subacute thyroiditis

Background

Subacute thyroiditis (SAT) is a self-limited disease commonly treated with prednisolone (PSL). The present study aimed to assess the effectiveness and safety of the new treatment protocol which consisted of PSL and Prunella vulgaris (PV) to reduce the dosage and incidence of side effects from PSL.

Methods

Data regarding the patients with SAT treated at the First Affiliated Hospital, School of Medicine, Zhejiang University between September 2013 and May 2016 were retrospectively analyzed. Patients treated with PSL only or a combination of PSL and PV were divided into two groups.

Results

In total, 87 patients were included. Patients treated with PSL and PV showed a similar remission rate to the patients who received only PSL. The recurrence rate (4.4% vs. 9.5%) and incidence of transient hypothyroidism (2.2% vs. 4.8%) were similar between the two groups (P=0.350 and P=0.517, respectively). Only two cases of a mild skin rash were recorded, and these were related to the use of PV.

Conclusions

The combination of low-dose PSL as a treatment choice for SAT was both effective and safe.

Subacute thyroiditis causing thyrotoxic crisis; a case report with literature review

INTRODUCTION

Subacute thyroiditis is a self-limited, inflammatory viral thyroid disease which presents with neck pain, usually accompanied by systemic symptoms. On the other hand, thyroid storm is a clinical condition of severe sudden hyperthyroidism accompanied by physiologic de-compensation. We presented a 29-year-old male with features of subacute thyroiditis and thyroid storm who is the third reported case managed by steroid, beta-blocker and analgesics.

CONCLUSION

subacute thyroiditis may present with thyrotoxic crisis which respond dramatically to corticosteroid therapy.

Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Patients with Autoimmune Thyroiditis

Clinical evidences have highlighted the efficacy of myo-inositol and selenium in the treatment of autoimmune thyroiditis. Aim of this study was to further analyze the role of myo-inositol plus selenium (Myo-Ins-Se) in restoring a normal thyroid function of Hashimoto's patients with subclinical hypothyroidism. Eighty-six patients with Hashimoto's thyroiditis having thyroid-stimulating hormone (TSH) levels between 3 and 6 mIU/L, elevated serum antithyroid peroxidase (TPOAb) and/or antithyroglobulin (TgAb), and normal free thyroxine (fT4) and free triiodothyronine (fT3) levels were enrolled in the study: one hyperthyroid subject with TSH about 0.14 μU/ml was included in this trial as a single case. Patients were assigned to receive Myo-Ins-Se. TSH, TPOAb, and TgAb levels were significantly decreased in patients treated with combined Myo-Ins-Se after 6 months of treatment. In addition, a significant fT3 and fT4 increase, along with an amelioration of their quality of life, was observed. Remarkably, TSH values of the hyperthyroid patient increased from 0.14 μU/ml up to 1.02 μU/ml, showing a complete restoration of TSH values at a normal range. In conclusion, the administration of Myo-Ins-Se is significantly effective in decreasing TSH, TPOAb, and TgAb levels, as well as enhancing thyroid hormones and personal wellbeing, therefore restoring euthyroidism in patients diagnosed with autoimmune thyroiditis.

Comparison of the therapeutic effects of prednisolone and nonsteroidal anti-inflammatory drugs in patients with subacute thyroiditis

Subacute thyroiditis is a transient inflammatory thyroid disease of unknown etiology. The primary goal for treatment is to mitigate inflammation. The aim of this retrospective study was to compare the therapeutic effects of prednisolone and nonsteroidal anti-inflammation drugs in patients with subacute thyroiditis. In this study, 53 consecutive Japanese patients who had been diagnosed with were referred to our hospital for further management. After excluding 11 patients (9 did not need treatment, 2 did not meet the criteria for diagnosis of subacute thyroiditis), the remaining 42 patients were treated either with prednisolone (n = 25) or loxoprofen (n = 17). We compared the time periods required for resolution of clinical symptoms and signs and normalization of thyroid function between the two groups. The mean dose of prednisolone was 15.0 (range, 14-16) mg/day and that of loxoprofen was 180 mg/day. The time period to normalization of thyroid function was comparable between the prednisolone and loxoprofen groups (25, 18-36, vs 32, 21-39 days, p = 0.388). However, the time period for resolution of symptoms was shorter under prednisolone than loxoprofen (7, 7-12 days, vs 21, 14-32 days, p < 0.001). Prednisolone treatment of patients with subacute thyroiditis was superior to nonsteroidal anti-inflammation drugs with regard to resolution of symptoms.

Thyroidectomy for Painful Thyroiditis Resistant to Steroid Treatment: Three New Cases with Review of the Literature

Thyroidal pain is usually due to subacute thyroiditis (SAT). In more severe forms prednisone doses up to 40 mg daily for 2-3 weeks are recommended. Recurrences occur rarely and restoration of steroid treatment cures the disease. Rarely, patients with Hashimoto's thyroiditis (HT) have thyroidal pain (painful HT, PHT). Differently from SAT, occasional PHT patients showed no benefit from medical treatment so that thyroidectomy was necessary. We report three patients who did not show clinical response to prolonged high dose prednisone treatment: a 50-year-old man, a 35-year-old woman, and a 33-year-old woman. Thyroidectomy was necessary, respectively, after nine-month treatment with 50 mg daily, two-month treatment with 75 mg daily, and one-month treatment with 50 mg daily. The two women were typical cases of PHT. Conversely, in the first patient, thyroid histology showed features of granulomatous thyroiditis, typical of SAT, without fibrosis or lymphocytic infiltration, typical of HT/PHT, coupled to undetectable serum anti-thyroid antibodies. Our data (1) suggest that not only PHT but also SAT may show resistance to steroid treatment and (2) confirm a previous observation in a single PHT patient that increasing prednisone doses above conventional maximal dosages may not be useful in these patients.

[Endocrine disease symptoms]

Diseases of the endocrine system can be classified according to the prevalence into two categories: very frequent endocrinopathies, which affect a population of several millions in Germany and include diabetes mellitus, endemic goiter, osteoporosis and obesity. On the other hand there are a large number of rare endocrine diseases which share the paradox of other rare diseases: they are also often falsely suspected in patients who are not affected but at the same time there are sometimes long delays in diagnosis in those who do have the disease. In cases of adrenal insufficiency, absolute glucocorticoid deficiency can progress to an adrenal crisis which is fatal if not treated. Patients with de Quervain thyroiditis often suffer from prolonged episodes of fever with tender, diffuse goiter and neck pain. Pheochromocytomas should be recognized early in the course of disease because of life-threatening cardiovascular complications. This article highlights the essential characteristics in order to increase awareness.

Initial treatment with 15 mg of prednisolone daily is sufficient for most patients with subacute thyroiditis in Japan

BACKGROUND

Oral glucocorticoids are administered in moderate and severe cases of subacute thyroiditis (SAT), providing dramatic relief from pain and fever. However, there have been no reports regarding the optimal dose of prednisolone (PSL) for treatment of SAT. In this study, we used 15 mg/day of PSL as the initial dosage and tapered it by 5 mg every 2 weeks. We assessed the effectiveness of this treatment protocol.

METHODS

We examined 384 consecutive and untreated patients with SAT who visited our thyroid clinic between February 2005 and December 2008. We excluded patients who did not fit our protocol, and the final number of subjects was 219. When patients complained of pain in their neck or C-reactive protein (CRP) was still high, physicians were able to extend the tapering of the dose of PSL or increase it at 2-week intervals. The endpoint of the study was the duration of the PSL medication. We also compared the severity of thyrotoxicosis and rate of hypothyroidism after SAT between the short medication group (patients who recovered within 6 weeks) and long medication group (patients who recovered in 12 weeks or more).

RESULTS

The number of patients whose thyroiditis improved within 6 weeks and did not recur was 113 (51.6%), and 61 (27.9%) improved within 7 to 8 weeks and did not have a recurrence. The longest duration was 40 weeks. Seven patients (3.2%) needed increases in the dosage of PSL. Thyroid hormone (free thyroxine and free triiodothyronine) levels measured at the initial visit in the short medication group were significantly higher than those in the long medication group (p<0.05). Serum CRP, male-to-female ratio, body weight, and age showed no differences between the two groups. There were no differences in the rate of hypothyroidism after SAT between the two groups (p=0.0632).

CONCLUSIONS

The treatment protocol that we employed had 15 mg/day of PSL as the initial dosage for the treatment of SAT, with tapering by 5 mg every 2 weeks, and was effective and safe for Japanese patients. However, 20% of patients with SAT needed longer than 8 weeks to recover from the inflammation.

Quick recovery of myocardium damage in a case of subacute thyroiditis

We describe a case of quick recovery of myocardium damage in a 15-year-old adolescent with subacute thyroiditis. After 1 week of admission, his cardiovascular status began to show signs of improvement accompanied by the recovery of electrocardiogram and indicators of myocardial damage. We speculate that myocardium damage associated with subacute thyroiditis is a complication of common virus, although we did not detect any abnormal virus antibody and deoxyribonucleic acid in the patient's serum.

Simultaneous occurrence of subacute thyroiditis and Graves' disease

BACKGROUND

Rare cases of Graves' disease occurring years after subacute thyroiditis (SAT) have been reported. Here, we present the first known case of simultaneous occurrence of Graves' disease and SAT.

PATIENT FINDINGS

A 41-year-old woman presented with 10 days of neck pain, dysphagia, and hyperthyroid symptoms. Neck pain had initially started at the base of the right anterior neck and gradually spread to her upper chest, the left side of her neck, and bilateral ears. Physical examination revealed a heart rate of 110 beats/minute and a diffusely enlarged tender thyroid gland without evidence of orbitopathy. There was a resting tremor of the fingers and brisk deep tendon reflexes. Laboratory values: thyrotropin<0.01 mcIU/mL (nL 0.39-5.33), free thyroxine 2.0 ng/dL (nL 0.59-1.60), free T3 6.6 pg/mL (nL 2.3-4.2), thyroglobulin 20.1 ng/mL (nL 2.0-35.0), thyroglobulin antibody 843 IU/mL (nL 0-80), thyroperoxidase antibody 130 IU/mL (nL 0-29), thyroid stimulating hormone receptor antibody 22.90 IU/L (nL<1.22), thyroid stimulating immunoglobulins 299 units (nL<140), erythrocyte sedimentation rate 120 mm/h (nL 0-20), and C-reactive protein 1.117 mg/dL (nL 0-0.5). Human leukocyte antigen (HLA) typing revealed DRB1, DR8, B35, B39, DQB1, DQ4, and DQ5. A thyroid ultrasound showed an enlarged heterogeneous gland with mild hypervascularity. Fine-needle aspiration (FNA) biopsies of both thyroid lobes revealed granulomatous thyroiditis. The thyroid scan showed a diffusely enlarged gland and heterogeneous trapping. There was a focal area of relatively increased radiotracer accumulation in the right upper pole. The 5-hour uptake ((123)I) was 6.6% (nL 4-15). The patient was symptomatically treated. Over the next several weeks, she developed hypothyroidism requiring levothyroxine treatment.

SUMMARY

This case illustrates a rare simultaneous occurrence of Graves' disease and SAT. Previous case studies have shown that Graves' disease may develop months to years after an episode of SAT. A strong family history of autoimmune thyroid disorders was noted in this patient. Genetic predilection was also shown by HLA typing.

CONCLUSION

Although the occurrence of SAT with Graves' disease may be coincidental, SAT-induced autoimmune alteration may promote the development of Graves' disease in susceptible patients. Genetically mediated mechanisms, as seen in this patient by HLA typing and a strong family history, may also be involved.

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.

de Quervain thyroiditis in a young boy following hand-foot-mouth disease

de Quervain thyroiditis, also known as subacute thyroiditis, is a self-limited inflammatory disease of the thyroid gland. It is extremely rare in children. The hallmarks for diagnosis are painful thyroid enlargement, elevated inflammatory markers, and decreased uptake of the thyroid gland on thyroid scintigraphy. Viral infection has been proposed to be associated with de Quervain thyroiditis. Coxsackie virus has been reported to be one of the viruses associated with the disease. To our knowledge, childhood de Quervain thyroiditis associated with hand-foot-mouth disease caused by coxsackie infection has never been reported. We report a 2.7-year-old boy who presented with typical features of de Quervain thyroiditis following hand-foot-mouth disease caused by coxsackie B4 infection. He had a brief thyrotoxic phase initially, followed by transient hypothyroid phase and euthyroidism thereafter. His thyroid scintigraphy showed a typical faint uptake at the diagnosis, and an improvement of the thyroid scan and uptake was shown 8 weeks later. He was treated with prednisolone and nearly complete resolution was documented within 2 months. Careful evaluation of the patient led to the correct diagnosis and appropriate management.

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.

Papillary carcinoma obscured by complication with subacute thyroiditis: sequential ultrasonographic and histopathological findings in five cases

BACKGROUND

Subacute thyroiditis (SAT) has been rarely reported to coexist with thyroid carcinomas. The objective of the study was to assess sequential ultrasonographic and histopathological findings of SAT in the context of complicating thyroid carcinomas.

METHODS

Of 1152 patients with SAT who visited our thyroid clinic at Kuma Hospital from 1996 through 2006, 5 cases complicated by papillary carcinoma underwent surgical resection 3-16 months after SAT onset. Ultrasonographic examinations and thyroid function tests were performed in all patients at onset of SAT and just before surgery. Sequential histopathological features of regenerated thyroid and carcinoma involvement were evaluated.

RESULTS

Heterogenous areas with microcalcifications in the thyroid or lymphadenopathy in three patients were clues for the nodular involvement with papillary carcinoma on the initial ultrasonographic examination. In contrast, diffuse hypoechoic change in the thyroid in two patients made it impossible to differentiate nodular involvement from inflammatory lesion. Histopathological examination of surgical specimens showed granulomatous and fibrotic changes. These were present about 3 months from SAT onset, and residual fibrosis remained several additional months, in the condition of no inflammatory hypoechoic lesions. In the areas of papillary carcinoma overlapping with transient inflammatory involvement, some lymphocytes and fibrotic changes were present in the stroma of papillary foci, but no granulomatous formation was present in any sections. Continuity with fibrosis around regenerated follicular cells was absent. The degree of lymphoid infiltrate and fibrotic change in the papillary carcinoma was not dependent on periods between SAT onset and the resection.

CONCLUSIONS

SAT may produce ultrasound changes that obscure the coexistence of papillary carcinoma, but affects no lymphoid infiltrate and fibrotic changes involved in carcinoma throughout the clinical course. We recommend that patients with SAT have ultrasonography after they recover. Further workup, including cytological examination of hypoechoic regions, should be performed if they are present as measuring 1 cm or larger.

Eye signs and serum eye muscle and collagen XIII antibodies in patients with transient and progressive thyroiditis

BACKGROUND

There have been reports of the development of ophthalmopathy in patients with subacute thyroiditis (SAT) in the absence of Graves' disease and thyroid-stimulating hormone receptor (TSH-r) antibodies.

OBJECTIVE

The aim of the study was to determine the prevalences of eye and eyelid signs and positive eye muscle and collagen XIII antibody tests in patients with SAT and silent thyroiditis (ST) and in patients with Hashimoto's thyroiditis (HT) as chronic thyroiditis controls.

DESIGN

Ophthalmopathy was classified as Nunery type 1 (orbital inflammation, proptosis, without restrictive myopathy) or Nunery type 2 (with restrictive myopathy). We tested for antibodies against calsequestrin, flavoprotein (Fp), G2s, and collagen XIII in 5 patients with SAT, 6 with ST, and 11 with HT, and in 12 age- and sex-matched healthy subjects, using an optimized and standardized enzyme-linked immunosorbent assay (ELISA).

MAIN OUTCOME

At the first visit, eye signs were found in two patients with SAT, one with type 1 ophthalmopathy and one with type 2 ophthalmopathy, and in three patients with ST, two with type 1 ophthalmopathy and one with dominant upper eyelid retraction only. Later in the course of their illness, one other patient with ST developed mild type 1 disease, giving an overall prevalence of any eye signs of 50% in patients with TT. Five patients with HT had mild type 1 ophthalmopathy and dominant upper eyelid retraction. One or more eye muscle antibodies were detected in three patients with SAT, four with ST, and seven with HT, of which calsequestrin and Fp antibodies were the most commonly found. TSH-r antibodies were detected in only one patient with ST, at the time when she developed Graves' hyperthyroidism following an episode of ST.

CONCLUSION

The development of mild, but definite, ophthalmopathy or dominant upper eyelid retraction in patients with TT and chronic (Hashimoto's) thyroiditis in the absence of TSH-r antibodies or Graves' hyperthyroidism is an interesting observation that should be further addressed in larger groups of patients, including those with postpartum thyroiditis. These preliminary findings also raise questions about the mechanism for the link between ophthalmopathy and thyroid autoimmunity.

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.

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.

Cervical Lymphadenitis, Suppurative Parotitis, Thyroiditis, and Infected Cysts

Neck masses are common and have a variety of infectious agents and noninfectious causes. This article reviews the more common infectious causes of neck masses-cervical lymphadenitis, suppurative parotitis, thyroiditis, and infected cysts. Important clinical pearls, diagnostic evaluation including laboratory studies, and imaging are summarized. Methods for prevention are highlighted.

Four cases of Graves' disease which developed after painful Hashimoto's thyroiditis

We report four cases of Graves' disease that developed after painful Hashimoto's thyroiditis. All were middle-aged women, who had high titers of anti-thyroid antibodies and thyrotoxicosis at the onset of painful Hashimoto's thyroiditis. After 2 to 7 years, they developed Graves' disease with positive antibody against the thyrotropin receptor. Their clinical courses of Graves' disease went favorably due to the treatment with antithyroid drug or radioactive iodine therapy. Painful Hashimoto's thyroiditis is an atypical variant of Hashimoto's thyroiditis and is one form of destructive thyroiditis. Thyroid damage due to painful Hashimoto's thyroiditis may be associated with the development of Graves' disease.

Successful treatment for recurrent painful Hashimoto's thyroiditis by total thyroidectomy

Painful Hashimoto's thyroiditis is an atypical variant of Hashimoto's thyroiditis characterized by thyroid pain and fever. In patients with this condition, anti-inflammatory agents are not always effective as in those with subacute thyroiditis. Therefore, long-term pain management is an important issue. We report herein four cases of painful Hashimoto's thyroiditis requiring total thyroidectomy to relieve thyroid pain and histologic findings of the thyroid gland. All patients had high titers of anti-thyroperoxidase (TPO) and thyroglobulin antibodies. Three were hypothyroid, and the other was euthyroid. During the first visit, four patients had fever and/or thyroid pain with elevated C-reactive protein or erythrocyte sedimentation rate, and they were treated with oral corticosteroids given continuously or intermittently for 9 to 48 months. Because a reduction or discontinuation of corticosteroids caused recurrent painful attacks, the decision was made to perform surgery. After total thyroidectomy, their symptoms disappeared. The histopathologic characteristics of these hypothyroid cases were advanced fibrosis and destructive thyroid architecture. One euthyroid case showed a mild fibrous change and the presence of foreign body type giant cells. In conclusion, total thyroidectomy is the effective and reliable treatment for patients with recurrent painful Hashimoto's thyroiditis. Pathologic characteristics include advanced fibrosis and destructive thyroid architecture.

[Inflammatory diseases of the thyroid gland. Epidemiology, symptoms and morphology]

Inflammation of the thyroid gland makes up approximately 20% of all thyroid diseases. According to the clinical course, thyroiditis has been subdivided into acute, subacute, and chronic forms. Recent classifications are based on the fact that the majority of thyroiditis cases have an autoimmune background. The most common form of this disease is autoimmune thyroiditis (AIT), with or without subclinical/manifest hypothyroidism; less common forms of autoimmune thyroiditis comprise subacute granulomatous (de Quervain's) thyroiditis, postpartum thyroiditis, silent ("painless") thyroiditis, and invasive-sclerosing thyroiditis (Riedel's thyroiditis). Non-autoimmune thyroiditis is very rare (acute suppurative thyroiditis, radiation thyroiditis). Thyroiditis is both clinically and morphologically an important differential diagnosis of thyroid tumours. The present paper deals with the epidemiology, clinical course, and morphology of thyroiditis, knowledge of which is essential for the examination of cytological and histological thyroid specimens.

Hyperthyroidism

Hyperthyroidism is a pathological syndrome in which tissue is exposed to excessive amounts of circulating thyroid hormone. The most common cause of this syndrome is Graves' disease, followed by toxic multinodular goitre, and solitary hyperfunctioning nodules. Autoimmune postpartum and subacute thyroiditis, tumours that secrete thyrotropin, and drug-induced thyroid dysfunction, are also important causes. The diagnosis of hyperthyroidism is generally straightforward, with raised serum thyroid hormones and suppressed serum thyrotropin in almost all cases. Appropriate treatment of hyperthyroidism relies on identification of the underlying cause. Antithyroid drugs, radioactive iodine, and surgery are the traditional treatments for the three common forms of hyperthyroidism. Beta-adrenergic blocking agents are used in most patients for symptomatic relief, and might be the only treatment needed for thyroiditis, which is transient. The more unusual causes of hyperthyroidism, including struma ovarii, thyrotropin-secreting tumours, choriocarcinoma, and amiodarone-induced thyrotoxicosis are, more often than not, a challenge to diagnose and treat.

Scintigraphic manifestations of thyrotoxicosis

The term thyrotoxicosis refers to the clinical syndrome of increased systemic metabolism that results when the serum concentrations of free thyroxine, free triiodothyronine, or both are elevated. The term hyperthyroidism refers to overactivity of the thyroid gland with a resultant increase in thyroid hormone synthesis and release into the systemic circulation. These terms are not interchangeable, since thyrotoxicosis can develop in thyroid conditions that are not associated with increased thyroid function, such as thyroiditis, or in so-called factitious hyperthyroidism. The clinical signs and symptoms of thyrotoxicosis are virtually identical regardless of the cause. However, in a given patient, every attempt should be made to determine the exact cause of the thyrotoxicosis, as this in turn determines the prognosis and treatment. Since thyroid scintigraphy demonstrates the functional state of the thyroid gland, it should be used, in conjunction with determination of radioactive iodine uptake, as the imaging modality of choice for diagnosis of thyrotoxicosis. Although the scintigraphic features of several of the thyroid disorders that cause thyrotoxicosis may overlap, their recognition helps narrow the differential diagnosis, thereby guiding the referring physician in the work-up and management of this disorder.

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.

[Subacute thyroiditis with cell destruction and temporary hyperthyroidism in Graves'disease--case report]

We present the case of a 60-year old woman with painful swelling of the thyroid gland and temporary thyrotoxicosis. 30 years ago she had experienced a period of hyperthyroidism because of Graves' disease. This time thyrotropin-receptor-antibodies were negative, Tc-99 m scan revealed decreased uptake in both lobes (this pattern normalised later on) and fine needle aspiration presented leucocyte infiltration of the thyroid. Three months later hypothyroidism was observed requiring treatment with levothyroxine. The development of subacute thyroiditis and Graves' disease in the same person is rare, autoimmune factors and a possible relationship are discussed.

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.

Thyroid ultrasound

Evaluation of the thyroid gland can be performed by several imaging techniques. Although ultrasound (US) lacks specificity for tissue diagnosis and can rarely distinguish benign from malignant disease, it can distinguish solid nodules from simple and complex cysts. It allows accurate estimation of thyroid size, gives a rough estimate of tissue density (echogenicity), shows vascular flow and velocity (color-flow Doppler), can identify regional lymphadenopathy, and aids in the accurate placing of needles for diagnostic or therapeutic purposes. In addition, it is widely available, relatively rapid and cheap, visualizes the whole anterior neck, and does not involve ionizing irradiation. This article aims at clarifying the role of US in clinical thyroidology by pointing to areas where the technology can aid in clinical decision making. It is argued that more clinician endocrinologists should master and use this technology for diagnostic and therapeutic purposes.

Diagnosis and Management of Infectious Thyroiditis

A broad range of disorders can cause inflammation of the thyroid gland. True thyroid infections are rare and can result from a variety of microorganisms, of which bacteria are the most common. Other rarer pathogens include fungi, parasites, and viruses. Gram-positive bacteria, especially staphylococci, predominate as causative agents in adults and children. In immunocompromised patients, opportunistic pathogens have been isolated. Most infections in adults occur as a result of hematogenous or lymphatic seeding of the thyroid gland. In children, congenital anomalies can lead to thyroid infection and require surgical correction to prevent recurrence. Fine-needle aspiration of the thyroid is usually required to identify the infecting agent, and prolonged antimicrobial therapy with or without surgical drainage is the cornerstone of management. This review outlines the pathogenesis, microbiology, diagnosis, and management of infectious thyroiditis in adults and children and compares this disorder with other, more common causes of thyroid inflammation.

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.

The value of ultrasonography in the diagnosis and follow-up of subacute thyroiditis

Twenty-three consecutive patients with clinical and biochemical suspicion of subacute thyroiditis (SAT) were evaluated by ultrasonic scanning of the thyroid. Ultrasonic findings supported the diagnosis in all cases. In the 16 patients in whom thyroid scintigraphy was performed this was compatible with SAT. Initially, median thyroid volume was 40 mL (range 20-289) and a very low echogenicity was demonstrated in all patients. The extension of hypoechogenicity exceeded 75% in the majority of patients. Thyroid volume was significantly reduced to a median of 13 mL (range 9-40) (68% reduction, p < 0.00001) at a median follow-up period of 18 months (range 6-33) and a majority of the patients (60%) had persistent morphological abnormalities. No correlation between thyroid function and the extension of hypoechogenicity initially or at end of follow-up could be demonstrated. Recurrence was noted in 8 patients (35%), two of whom were positive for anti-TPO antibodies, but the risk of recurrence could not be correlated to the extension of hypoechogenicity or initial thyroid function. Recurrence was related to the further extention of hypoechoic areas and increase in thyroid volume, as evidenced by ultrasonography in our series. None developed thyroid antibodies, and all were euthyroid at the end of the observation period. We believe that high resolution ultrasonography has a useful supporting role in the diagnosis of subacute thyroiditis. In case of doubt and differential diagnostic considerations, it facilitates guided biopsies. Additionally, it allows determination of disease activity and thyroid size.

The transition of subacute thyroiditis to Graves' disease as evidenced by diagnostic imaging

The development of Graves' disease as evidenced by diagnostic imaging and appearance of TSH receptor antibodies is described in a 49-year-old woman 6 months after onset of subacute thyroiditis. The HLA typing indicated that the patient had a genetic predisposition to hyperthyroid Graves' disease as well as subacute thyroiditis. A possible causal relationship is discussed.