The effect of COVID-19 on the presentation of thyroid disease in children

Thyroiditis and COVID-19: focus on pediatric age. A narrative review

PURPOSE

In light of the growing concern over the possible link between SARS-CoV2 infection and autoimmune diseases, we conducted a review to investigate the impact of the pandemic outbreak on thyroid diseases.

METHODS

We carried out a narrative review of all pediatric cases described in the literature, mainly focusing on the possible association of COVID-19 with the incidence of autoimmune and post-infective thyroid diseases (namely Hashimoto's Thyroiditis (HT), Grave's Disease (GD) and Sub-Acute Thyroiditis (SAT)). We also felt it was necessary to provide a brief review of Non-thyroidal Illness Syndrome (NTIS) and Multisystem Inflammatory Syndrome in Children (MIS-C) because of their overlap with thyroiditis.

RESULTS

There is currently no conclusive evidence linking SARS-CoV-2 infection with an increased incidence of autoimmune thyroiditis (AT) in pediatric age. However, SAT may be a mild complication of SARS-CoV-2 infection, as is the case with other viral infections. SAT typically resolves on its own and does not require treatment. NTIS may be associated with inflammatory complications, such as MIS-C, and admission to intensive care. It may also be considered a prognostic risk factor for severe disease. The hypothesized pathogenetic mechanisms of thyroid damage in COVID-19 include direct damage due to the significant expression of angiotensin-converting enzyme 2 (ACE2) in the thyroid gland, which is a ligand for the virus, and indirect damage due to immune dysregulation, such as the overproduction of IL-6, which is thought to be part of the pathogenesis of thyroiditis.

CONCLUSION

However, due to the limited evidence available, further prospective longitudinal studies are required to clarify the relationship between COVID-19 and thyroid disease in children and adolescents, as well as to investigate any potential long-term consequences.

SARS-CoV-2 and thyroid diseases

SARS-CoV-2 virus responsible for acute respiratory disease affected other organs leading to co-existence symptoms or complications. Thyroid gland was one of them due to expression of angiotensin-converting enzyme 2 (ACE2), the protein facilitating viral binding to the host cells. Moreover, thyroid gland, important for regulation of hormonal network, is extremely sensitive to any changes in homeostasis and metabolism. It was shown, that COVID-19 was associated with induction of thyroid disease or increasing existing functional disturbances or autoimmune process. Thyroid diseases are mainly based on immunological pathomechanism although the relation between immune system and thyroid function is bidirectional e.g. thyroid hormones modulate specific immune responses, including cell-mediated immunity, NK cell activity, the production of antiviral interferon (IFN) and proliferation of T- and B-lymphocytes. The effects of COVID-19 and mRNA vaccine on thyroid function and diseases are discussed.

Endocrinological Involvement in Children and Adolescents Affected by COVID-19: A Narrative Review

Since the advent of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, an increased incidence of several endocrinological anomalies in acute-phase and/or long-term complications has been described. The aim of this review is to provide a broad overview of the available literature regarding changes in the worldwide epidemiology of endocrinological involvement in children since December 2019 and to report the evidence supporting its association with coronavirus disease 2019 (COVID-19). Although little is known regarding the involvement of endocrine organs during COVID-19 in children, the current evidence in adults and epidemiological studies on the pediatric population suggest the presence of a causal association between the virus and endocrinopathies. Untreated transient thyroid dysfunction, sick euthyroid syndrome, nonthyroidal illness syndrome, and hypothalamic-pituitary-adrenal (HPA) axis and central precocious puberty have been observed in children in acute infection and/or during multisystem inflammatory syndrome development. Furthermore, a higher frequency of ketoacidosis at onset in children with a new diagnosis of type 1 diabetes is reported in the literature. Although the direct association between COVID-19 and endocrinological involvement has not been confirmed yet, data on the development of different endocrinopathies in children, both during acute infection and as a result of its long-term complications, have been reported. This information is of primary importance to guide the management of patients with previous or current COVID-19.

Endocrine manifestations of COVID-19 in children: A scoping review

In this review, we explore associations between SARS CoV-2 infection and the endocrine system and metabolism in children and adolescents. PubMed, Scopus and Google scholar databases were searched to identify published data on endocrine manifestations of COVID-19 in children up to 31 March 2023, including diabetes, obesity, puberty, thyroid disorders, adrenal disorders and pituitary disorders. Data on changes in disease pattern/ incidence, disease control, and other effects due to the COVID-19 pandemic, as well as effects of pre-existing endocrine conditions on severity of COVID-19 infection are presented, and practice points and research needs provided under each section.

Differences in the clinical picture at the onset of diagnosis of severe autoimmune hypothyroidism in children depending on the time of diagnosis: before or during the SARS-CoV-2 pandemic

INTRODUCTION

There are few data about effects of COVID-19 on thyroid disease presentation in children, due to difficulties in healthcare services access.

AIM OF THE STUDY

To assess the differences in hypothyroidism presentation before and during the COVID-19 pandemic.

MATERIAL AND METHODS

All paediatric patients with autoimmune hypothyroidism (AIT) diagnosed from January 2017 to December 2022 were analysed.

RESULTS

A total of 150 subjects were enrolled (94 in before and 56 during the pandemic period). Severe AIT was detected in 7.4% before and 12.5% during the pandemic. Age at the onset in the pre-pandemic period was lower ( p = 0.04). Diagnosis delay (time elapsed from onset of symptoms and diagnosis) was significantly different between the before and during the pandemic groups ( p = 0.02). In the pre-pandemic period the TSH value was 447.7 ±59.1, and it was 713.7 ±104.4 mUI/l during the pandemic ( p = 0.04), whereas mean fT4 values were 2.66 ±0.34 and 0.58 ±0.08 ng/l, respectively ( p = 0.0002). Significantly greater thyroid volume and bone age delay SDS were observed during the pandemic ( p = 0.04). Neurological symptoms were mostly observed during the pandemic, especially slow speech and impaired school performance.

CONCLUSIONS

A higher rate of severe AIT was observed during the pandemic period, mostly related to difficulties in access to healthcare services. The diagnosis delay led to a more severe biochemical thyroid hormone profile, goitre, and more frequent presence of bone age delay and neurological symptoms at the onset. Recognizing hypothyroidism and recalling symptoms in child-hood, even if often non-specific, is fundamental for avoiding diagnosis delay.