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

Risk of Incident Thyroid Dysfunction in the Post-Acute Phase of COVID-19: A Population-Based Cohort Study in Hong Kong

OBJECTIVE

The evidence of thyroid dysfunction in the post-acute phase of SARS-CoV-2 infection is limited. This study aimed to evaluate the risk of incident thyroid dysfunction in the post-acute phase of COVID-19.

METHODS

This retrospective, propensity-score matched, population-based study included COVID-19 patients and non-COVID-19 individuals between January 2020 and March 2022, identified from the electronic medical records of the Hong Kong Hospital Authority. The cohort was followed up until the occurrence of outcomes, death, or 31 January 2023, whichever came first. Patients with COVID-19 were 1:1 matched to controls based on various variables. The primary outcome was a composite of thyroid dysfunction (hyperthyroidism, hypothyroidism, initiation of antithyroid drug or levothyroxine, and thyroiditis). Cox regression was employed to evaluate the risk of incident thyroid dysfunction during the post-acute phase.

RESULTS

A total of 84 034 COVID-19 survivors and 84 034 matched controls were identified. Upon a median follow-up of 303 days, there was no significant increase in the risk of diagnosed thyroid dysfunction in the post-acute phase of COVID-19 (hazard ratio [HR] 1.058, 95% confidence interval 0.979-1.144, P = .154). Regarding the secondary outcomes, patients with COVID-19 did not have increased risk of hyperthyroidism (HR 1.061, P = .345), hypothyroidism (HR 1.062, P = .255), initiation of antithyroid drug (HR 1.302, P = .070), initiation of levothyroxine (HR 1.086, P = .426), or thyroiditis (P = .252). Subgroup and sensitivity analyses were largely consistent with the main analyses.

CONCLUSION

Our population-based cohort study provided important reassuring data that COVID-19 was unlikely to be associated with persistent effects on thyroid function.

Thyroid dysfunction in COVID-19

The COVID-19 pandemic has affected over 772 million people globally. While lung damage is the major contributor to the morbidity and mortality of this disease, the involvement of multiple organs, including the endocrine glands, has been reported. This Review aims to provide an updated summary of evidence regarding COVID-19 and thyroid dysfunction, incorporating highlights of recent advances in the field, particularly in relation to long COVID and COVID-19 vaccination. Since subacute thyroiditis following COVID-19 was first reported in May 2020, thyroid dysfunction associated with COVID-19 has been increasingly recognized, secondary to direct and indirect effects on the hypothalamic-pituitary-thyroid axis. Here, we summarize the epidemiological evidence, pattern and clinical course of thyroid dysfunction following COVID-19 and examine radiological, molecular and histological evidence of thyroid involvement in SARS-CoV-2 infection. Beyond acute SARS-CoV-2 infection, it is also timely to examine the course and implication of thyroid dysfunction in the context of long COVID owing to the large population of survivors of COVID-19 worldwide. This Review also analyses the latest evidence on the relationship between the therapeutics and vaccination for COVID-19 and thyroid dysfunction. To conclude, evidence-based practice recommendations for thyroid function testing during and following COVID-19 and concerning COVID-19 vaccination are proposed.

HLA typing of patients who developed subacute thyroiditis and Graves' disease after SARS-CoV-2 vaccination: a case report

BACKGROUND

Cases of subacute thyroiditis (SAT) after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination have been reported. A human leukocyte antigen (HLA) allele, HLA-B*35, appears to be involved in the pathogenesis of SAT.

CASE PRESENTATION

We conducted HLA typing of one patient with SAT and another with both SAT and Graves' disease (GD), which developed after SARS-CoV-2 vaccination. Patient 1, a 58-year-old Japanese man, was inoculated with a SARS-CoV-2 vaccine (BNT162b2; Pfizer, New York, NY, USA). He developed fever (38 °C), cervical pain, palpitations, and fatigue on day 10 after vaccination. Blood chemistry tests revealed thyrotoxicosis and elevated serum C-reactive protein (CRP) and slightly increased serum antithyroid-stimulating antibody (TSAb) levels. Thyroid ultrasonography revealed the characteristic findings of SAT. Patient 2, a 36-year-old Japanese woman, was inoculated twice with a SARS-CoV-2 vaccine (mRNA-1273; Moderna, Cambridge, MA, USA). She developed fever (37.8 °C) and thyroid gland pain on day 3 after the second vaccination. Blood chemistry tests revealed thyrotoxicosis and elevated serum CRP, TSAb, and antithyroid-stimulating hormone receptor antibody levels. Fever and thyroid gland pain persisted. Thyroid ultrasonography revealed the characteristic findings of SAT (i.e., slight swelling and a focal hypoechoic area with decreased blood flow). Prednisolone treatment was effective for SAT. However, thyrotoxicosis causing palpitations relapsed thereafter, for which thyroid scintigraphy with ^99mtechnetium pertechnetate was conducted, and the patient was diagnosed with GD. Thiamazole treatment was then initiated, which led to improvement in symptoms.

CONCLUSION

HLA typing revealed that both patients had the HLA-B*35:01, -C*04:01, and -DPB1*05:01 alleles. Only patient 2 had the HLA-DRB1*11:01 and HLA-DQB1*03:01 alleles. The HLA-B*35:01 and HLA-C*04:01 alleles appeared to be involved in the pathogenesis of SAT after SARS-CoV-2 vaccination, and the HLA-DRB1*11:01 and HLA-DQB1*03:01 alleles were speculated to be involved in the postvaccination pathogenesis of GD.

Clinical, biochemical features and functional outcome of patients with SARS-CoV-2-related subacute thyroiditis: a review

INTRODUCTION

SARS CoV-2 infection involves many organs and systems, including the thyroid, in which it manifests itself as subacute thyroiditis (SAT). After our first description of SAT due to SARS-CoV2 infection, other reports have confirmed the correlation between SARS-CoV-2 and SAT. We review the cases of SAT associated with COVID-19 to highlight its peculiar clinical and biochemical features, including its outcome and what it has added to our understanding of SAT.

RESULTS

We have reviewed 24 articles, for a total of 69 cases of SAT related to SARS-CoV2 infection. All had neck pain, whereas thyrotoxicosis was documented in 68/68 who had their thyroid function checked. Ultrasound, performed in 67 patients, was typical of SAT in 65 and low uptake at scintigraphy was demonstrated in all 12 evaluated patients. Patients had a prompt response to the anti-inflammatory and/or glucocorticoid therapy, as expected in SAT. The rate of hypothyroidism was higher (36.5%) in COVID-19-related SAT compared to that observed in the pre-COVID era (10%).

CONCLUSIONS

Clinical, biochemical, and instrumental features of SAT related to SARS-CoV2 are like those observed in SAT cases reported prior to COVID-19 pandemic, but it appears more severe.

ACE2 in male genitourinary and endocrine systems: Does COVID-19 really affect these systems?

The virus that causes COVID-19 (Corona Virus Disease 2019), SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), is causing a worldwide pandemic, posing a substantial threat to human health. Patients show signs of pneumonia, ARDS, shock, acute cardiac injury, acute kidney injury and other complications. The SARS-CoV-2 receptor is angiotensin converting enzyme 2 (ACE2), which is an important component of the renin-angiotensin system (RAS). In addition, TMPRSS2 or other cofactors are needed to allow the virus to enter the host. Clinical patients have exhibited varying degrees of genitourinary and endocrine system damage, and some studies have also reported potential risks to the genitourinary and endocrine systems. This article reviews the mechanism underlying SARS-CoV-2 infection and the current studies on the male genitourinary and endocrine systems and proposes that more attention should be directed towards human reproductive and endocrine health during the SARS-CoV-2 epidemic.

The Influence of SARS-CoV-2 Infection on the Thyroid Gland

It is important to acknowledge the impact that COVID-19 has on the thyroid gland and how the thyroid gland status before and during infection affects SARS-CoV-2 severity. To this day those dependencies are not fully understood. It is known that the virus uses angiotensin-converting enzyme-2 as the receptor for cellular entry and it can lead to multiple organ failures due to a cytokine storm. Levels of proinflammatory molecules (such as cytokines and chemokines) which are commonly elevated during infection were significantly higher in observed SARS-CoV-2-positive patients. In terms of hypothyroidism, hyperthyroidism, and autoimmune thyroid diseases, there is no proof that those dysfunctions have a direct impact on the more severe courses of COVID-19. Regarding hyper- and hypothyroidism there was no consequential dependency between the frequency of SARS-CoV-2 infection morbidity and more severe post-infectious complications. When it comes to autoimmune thyroid diseases, more evaluation has to be performed due to the unclear relation with the level of antibodies commonly checked in those illnesses and its binding with the mentioned before virus. Nonetheless, based on analyzed works we found that COVID-19 can trigger the immune system and cause its hyperactivity, sometimes leading to the new onset of autoimmune disorders. We also noticed more acute SARS-CoV-2 courses in patients with mainly reduced free triiodothyronine serum levels, which in the future, might be used as a mortality indicating factor regarding SARS-CoV-2-positive patients. Considering subacute thyroiditis (SAT), no statistically important data proving its direct correlation with COVID-19 infection has been found. Nevertheless, taking into account the fact that SAT is triggered by respiratory tract viral infections, it might be that SARS-CoV-2 can cause it too. There are many heterogenous figures in the symptoms, annual morbidity distribution, and frequency of new cases, so this topic requires further evaluation.

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.

Endocrine Disorders and COVID-19

The multifaceted interaction between coronavirus disease 2019 (COVID-19) and the endocrine system has been a major area of scientific research over the past two years. While common endocrine/metabolic disorders such as obesity and diabetes have been recognized among significant risk factors for COVID-19 severity, several endocrine organs were identified to be targeted by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). New-onset endocrine disorders related to COVID-19 were reported while long-term effects, if any, are yet to be determined. Meanwhile, the "stay home" measures during the pandemic caused interruption in the care of patients with pre-existing endocrine disorders and may have impeded the diagnosis and treatment of new ones. This review aims to outline this complex interaction between COVID-19 and endocrine disorders by synthesizing the current scientific knowledge obtained from clinical and pathophysiological studies, and to emphasize considerations for future research.

Thyroid function changes and COVID-19 severity: egg or chicken?

The novel coronavirus disease 2019 (COVID-19) produced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious infectious disease. In addition to typical flu-like symptoms, COVID-19 can also cause extrapulmonary spread and systemic inflammation, potentially causing multiorgan dysfunction, including thyroid dysfunction. Thyroid function changes in patients with COVID-19 have been widely reported, but the results are inconsistent. Based on available data, SARS-CoV-2 infection can lead to changes in thyroid function, and the degree of thyroid function changes was positively correlated with the severity of COVID-19, which involved multiple potential mechanisms. In contrast, current evidence was insufficient to prove that thyroid function changes could induce the progression of COVID-19 clinical deterioration.

Vitamin D and interferon-γ co-operate to increase the ACE-2 receptor expression in primary cultures of human thyroid cells

BACKGROUND

A more severe course of COVID-19 was associated with low levels of Vitamin D (VitD). Moreover in vitro data showed that VitD up-regulates the mRNA of the Angiotensin Converting Enzyme 2 (ACE-2), the SARS-COV-2 receptor in different type of cells. ACE-2 is expressed in several type of tissues including thyroid cells, on which its mRNA was shown to be up-regulated by interferon-gamma (IFN-γ). The aim of the present study was to investigate if treatment with VitD alone or in combination with IFN-γ would increase ACE-2 both at mRNA and protein levels in primary cultures of human thyrocytes.

MATERIALS AND METHODS

Primary thyroid cell cultures were treated with VitD and IFN-γ alone or in combination for 24 h. ACE-2 mRNA levels were measured by Real-time Polymerase Chain Reaction (RT-PCR). The presence of ACE-2 on thyroid cell membrane was assessed by immunocytochemistry basally and after the previous mentioned treatments.

RESULTS

ACE-2 mRNA levels increased after treatment with VitD and IFN-γ alone. The combination treatment (VitD + IFN-γ) showed an additive increase of ACE-2-mRNA. Immunocytochemistry experiments showed ACE-2 protein on thyroid cells membrane. ACE-2 expression increased after treatment with VitD and IFN-γ alone and further increased by the combination treatment with VitD + IFN-γ.

CONCLUSIONS

VitD would defend the body by SARS-COV2 both by regulating the host immune defense and by up-regulating of the expression of the ACE-2 receptor. The existence of a co-operation between VitD and IFN-γ demonstrated in other systems is supported also for ACE-2 up-regulation. These observations lead to an increased interest for the potential therapeutic benefits of VitD supplementation in COVID-19.

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.

Further understanding of thyroid function in pregnant women

INTRODUCTION

Normal thyroid status throughout pregnancy is important for both maternal and fetal health. Despite the bulk of contemporary research honing on thyroid function in gestation and the relevant disorders, there are still gaps in our current knowledge about the etiology and treatment of thyroid diseases in pregnant women.

AREAS COVERED

This article analyzes the adaptation of the thyroid gland to gestational physiological changes and attempts to explain the effect of several factors on thyroid function in pregnancy. It also stresses proper utilization and interpretation of thyroid tests during pregnancy and underlines the significance of proper screening and treatment of pregnant women aiming at favorable health outcomes.

EXPERT OPINION

Appropriate strategies for diagnosing and treating thyroid disease in pregnancy are important. Laboratory thyroid testing plays a leading role, but test results should be interpreted with caution. Given the possible serious maternal and fetal/neonatal complications of thyroid disease in pregnancy, we recommend universal screening with TSH measurements of all pregnant women. Additional assessment with determination of the levels of free thyroid hormones and thyroid antibodies may be necessary under certain conditions. The economic burden of such interventions should be considered.

A Case of Subacute Thyroiditis following COVID-19 Infection

Background/Objective. Since the start of the pandemic, COVID-19 has been associated with several postinfection complications. Subacute thyroiditis (SAT) is an inflammatory disorder of the thyroid that has been reported in the literature following COVID-19 infection. We report a case of SAT following COVID-19 infection. Case Report. A 33-year-old female presented with neck pain two weeks after resolution of COVID-19 infection. Her thyroid function tests together with ultrasonographic pictures were consistent with SAT. She was treated with three rounds of medrol dose pack without relief. She then required oral prednisone 40 mg per day and ibuprofen 800 mg once daily for another several weeks that eventually resulted in improvement of her symptoms. Discussion. SAT most commonly occurs in females during or after viral infection. The usual course of the disease is hyperthyroidism then hypothyroidism followed by resolution. SAT is clinically diagnosed by lab findings of decreased TSH in the setting of negative thyroid-stimulating and thyroid peroxidase antibodies. All these data are consistent with our case. Conclusion. SAT following COVID-19 infection presents with a similar clinical presentation and course as the classic form of SAT, but we should consider the fact that a high-dose corticosteroid treatment might be necessary for such patients.

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.

The New Entity of Subacute Thyroiditis amid the COVID-19 Pandemic: From Infection to Vaccine

This is a review of full-length articles strictly concerning subacute thyroiditis (SAT) in relation to the SARS-CoV-2 virus infection (SVI) and COVID-19 vaccine (COV) that were published between the 1st of March 2020 and the 21st of March 2022 in PubMed-indexed journals. A total of 161 cases were reported as follows: 81 cases of SAT–SVI (2 retrospective studies, 5 case series, and 29 case reports), 80 respective cases of SAT–COV (1 longitudinal study, 14 case series, 17 case reports; also, 1 prospective study included 12 patients, with 6 patients in each category). To our knowledge, this represents the largest cohort of reported cases until the present time. SAT–SVI was detected in adults aged between 18 and 85 years, mostly in middle-aged females. SAT–COVID-19 timing classifies SAT as viral (synchronous with infection, which is an original feature of SATs that usually follow a viral infection) and post-viral (during the recovery period or after infection, usually within 6 to 8 weeks, up to a maximum 24 weeks). The clinical spectrum has two patterns: either that accompanying a severe COVID-19 infection with multi-organ spreading (most frequent with lung involvement) or as an asymptomatic infection, with SAT being the single manifestation or the first presentation. Either way, SAT may remain unrecognized. Some data suggest that more intense neck pain, more frequent fever, and more frequent hypothyroidism at 3 months are identified when compared with non-SAT–SVI, but other authors have identified similar presentations and outcomes. Post-COVID-19 fatigue may be due to residual post-SAT hypothyroidism. The practical importance of SAT–SVI derives from the fact that thyroid hormone anomalies aggravate the general status of severe infections (particular concerns being tachycardia/arrhythmias, cardiac insufficiency, and ischemic events). If misdiagnosed, SAT results in unnecessary treatment with anti-thyroid drugs or even antibiotics for fever of unknown cause. Once recognized, SAT does not seem to require a particular approach when compared with non-COVID-19 cases, including the need for glucocorticoid therapy and the rate of permanent hypothyroidism. A complete resolution of thyroid hormone anomalies and inflammation is expected, except for cases with persistent hypothyroidism. SAT–COV follows within a few hours to a few weeks, with an average of 2 weeks (no particular pattern is related to the first or second vaccine dose). Pathogenesis includes molecular mimicry and immunoinflammatory anomalies, and some have suggested that this is part of ASIA syndrome (autoimmune/inflammatory syndrome induced by adjuvants). An alternative hypothesis to vaccine-related increased autoimmunity is vaccine-induced hyperviscosity; however, this is supported by incomplete evidence. From what we know so far concerning the risk factors, a prior episode of non-SVI–SAT is not associated with a higher risk of SAT–COV, nor is a previous history of coronavirus infection by itself. Post-vaccine SAT usually has a less severe presentation and a good outcome. Generally, the female sex is prone to developing any type of SAT. HLA susceptibility is probably related to both new types of SATs. The current low level of statistical evidence is expected to change in the future. Practitioners should be aware of SAT–COV, which does not restrict immunization protocols in any case.

Subacute thyroiditis during the COVID-19 pandemic: a prospective study

PURPOSE

Subacute thyroiditis(SAT) is a destructive thyroiditis associated with viral infections. Several SAT cases associated with SARS-CoV-2 infection/vaccination were recently reported. We aimed to evaluate prospectively all cases applied to our tertiary center and their relationship with SARS-CoV-2 during 16 months of the pandemic. Cases during similar pre-pandemic period were recorded for numeric comparison.

METHODS

Prospective study took place between March 2020 and July 2021. SAT was diagnosed by classical criteria. Swabs for SARS-CoV-2 and a wide respiratory viral panel (RV-PCR) were taken. Previous COVID-19 was assessed by SARS-CoV-2 IgM&IgG levels. Study group was divided into three as: CoV-SAT, patients who had or still have COVID-19, Vac-SAT, patients diagnosed within three months after SARS-CoV-2 vaccination and NonCoV-SAT, those not associated with COVID-19 or vaccination.

RESULTS

Out of 64 patients, 18.8% (n = 12) was classified as CoV-SAT, 9.3% (n = 6) as Vac-SAT and 71.9% as (n = 46) NonCoV-SAT. SARS-CoV-2 RT-PCR tests on the diagnosis of SAT were negative in all, but two patients tested positive five days later, in second testing, performed upon clinical necessity. CoV-SAT and NonCoV-SAT groups were similar in terms of clinical, laboratory, and treatment characteristics. However, symptoms were milder and treatment was easier in Vac-SAT group (p = 0.006).

CONCLUSIONS

Total number of SAT cases during the pandemic period was comparable to pre-pandemic period. However, a considerable rate of SARS-CoV-2 exposure in SAT patients was established. COVID-19 presented with SAT, as the first manifestation in three cases. Vaccine-related cases developed in a shorter time period, clinical presentation was milder, and only a few required corticosteroids.

Case Report: Hypothalamic Amenorrhea Following COVID-19 Infection and Review of Literatures

SARS-CoV-2 infection, responsible for the coronavirus disease 2019 (COVID-19), can impair any organ system including endocrine glands. However, hypothalamic-pituitary dysfunctions following SARS-CoV-2 infection remain largely unexplored. We described a case of hypothalamic amenorrhea following SARS-CoV-2 infection in a 36-year-old healthy woman. The diagnostic workup excluded all the causes of secondary amenorrhea, in agreement to the current guidelines, whereas the gonadotropin increase in response to GnRH analogue tests was suggestive for hypothalamic impairment. Therefore, since our patient did not present any organic cause of hypothalamic-pituitary disorder, we hypothesized that her hypothalamic deficiency may have been a consequence of SARS-CoV-2 infection. This assumption, besides on the temporal consecutio, is strengthened by the fact that SARS-CoV-2 infection can impair the hypothalamic circuits, altering the endocrine axes, given that angiotensin-converting enzyme 2 receptors have also been observed in the hypothalamus. We reviewed the literature regarding hypothalamic-pituitary dysfunction in patients with SARS-CoV-2 infection. No study has previously described female hypogonadotropic hypogonadism with secondary amenorrhea following COVID-19. We suggest clinicians focusing greater attention on this possible endocrine disorder.

COVID-19-Associated Subacute Thyroiditis: Evidence-Based Data From a Systematic Review

Subacute thyroiditis (SAT) is a thyroid disease of viral or post-viral origin. Whether SAT represents a complication of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still unclear. Our aim was to systematically review the literature to 1) explore the size of the literature about SAT in COVID-19 and 2) evaluate the clinical characteristics of SAT. PubMed/MEDLINE, Embase, and Scopus were searched until April 20, 2021. Original papers, case reports, and case series reporting SAT in COVID-19 patients were included. Authors and their country, journal, year of publication, COVID-19 and SAT clinical presentation, thyroid function, therapy, and follow-up data were extracted. Nineteen papers (17 case reports and 2 case series) were included, describing 27 patients, 74.1% females, aged 18 to 69 years. COVID-19 was diagnosed by nasopharyngeal swab in 66.7% cases and required hospitalization in 11.1%. In 83.3% cases, SAT occurred after COVID-19. Neck pain was present in 92.6% cases and fever in 74.1%. Median TSH, fT3, and fT4 were 0.01 mU/l, 10.79 pmol/l, and 27.2 pmol/l, respectively. C-reactive-protein and erythrocyte sedimentation rate were elevated in 96% of cases. Typical ultrasonographic characteristics of SAT were observed in 83.3% of cases. Steroids were the most frequent SAT therapy. Complete remission of SAT was recorded in most cases. In conclusion, the size and quality of published data of SAT in COVID-19 patients are poor, with only case reports and case series being available. SAT clinical presentation in COVID-19 patients seems to be similar to what is generally expected.