Hyperthyroidism in children

Management of Pediatric Graves Disease: A Review

Importance

The incidence of Graves disease (GD) is rising in children, and adequate care of these patients requires a multidisciplinary approach. Whether patients are seen in the context of endocrinology, nuclear medicine, or surgery, it is important to know the nuances of the therapeutic options in children.

Observations

Given the rarity of GD in children, it is important to recognize its various clinical presenting signs and symptoms, as well as the tests that may be important for diagnosis. The diagnosis is typically suspected clinically and then confirmed biochemically. Imaging tests, including thyroid ultrasonography and/or nuclear scintigraphy, may also be used as indicated during care. It is important to understand the indications for and interpretation of laboratory and imaging tools so that a diagnosis is made efficiently and unnecessary tests are not ordered. Clinicians should be well-versed in treatment options to appropriately counsel families. There are specific scenarios in which medical therapy, radioactive iodine therapy, or surgery should be offered.

Conclusions and Relevance

The diagnosis and treatment of pediatric patients with GD requires a multidisciplinary approach, involving pediatric specialists in the fields of endocrinology, ophthalmology, radiology, nuclear medicine, and surgery/otolaryngology. Antithyroid drugs are typically the first-line treatment, but sustained remission rates with medical management are low in the pediatric population. Consequently, definitive treatment is often necessary, either with radioactive iodine or with surgery, ideally performed by experienced, high-volume pediatric experts. Specific clinical characteristics, such as patients younger than 5 years or the presence of a thyroid nodule, may make surgery the optimal treatment for certain patients.

Age- and sex-specific reference intervals for thyroid hormones in a Chinese pediatrics: a prospective observational study of 1,279 healthy children

BACKGROUND

Thyroid hormones are essential for early neurocognitive development and growth and development in childhood and adolescence. However, the reference intervals (RIs) for thyroid hormones in Chinese pediatric individuals remain unclear. This study aimed to establish thyroid hormone RIs for a Chinese pediatric population according to appropriate age- and sex-specific partitioning.

METHODS

In this prospective observational study, a total of 1,279 healthy children (singletons, aged from 1 day to 12 years) were recruited, and serum samples were analyzed on a Mindray automated chemiluminescence immunoassay analyzer CL-6000i for thyroid hormone detection, including thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (T3), and total thyroxine (T4). Age and sex-specific RIs were established, and the corresponding 95% confidence intervals (CIs) were calculated in accordance with the Clinical Laboratory Standards Institute (CLSI) document C28-A3 guidelines.

RESULTS

Quantile testing revealed that the median (P50) and RIs [2.5^th percentile (P2.5)-97.5^th percentile (P97.5)] for TSH, FT3, T3, and T4 of males differed significantly from those of females (P<0.05), except for FT4 (P=0.483). For FT3 and T3, the RIs of males were higher than that of females, and the RI of T4 for males was narrower and higher than that of females [P2.5-P97.5: 72.33-171.60 vs. 72.31-176.27 nmol/L; P50: 116.75 vs. 113.47 nmol/L, P=0.011]. RIs for TSH, FT3, FT4, T3, and T4 showed sex- and age-specific properties and displayed a wide variation during the first month of life but gradually narrowed and concentrated with increasing age. In addition, RIs of TSH, FT3, FT4, and T3 in males differed significantly from females in the first month of life (TSH: 1.46-10.87 vs. 1.08-11.35 mIU/L; FT3: 2.96-7.08 vs. 2.35-7.27 pmol/L, FT4: 13.34-28.65 vs. 13.82-31.83 pmol/L; T3: 0.83-2.33 vs. 0.72-2.46 nmol/L). The RI of T4 also exhibited a difference between males and females in the 9- to 12-year age group (59.31-150.72 vs. 63.29-146.94 pmol/L for males and females, respectively).

CONCLUSIONS

Pediatric RIs of thyroid hormones display age- and sex-specific trends. The RIs established in this study will improve the accuracy of TSH assay result interpretations and clinical decision-making in clinical laboratories that utilize the Mindray analytical platform.

Neurological and gastrointestinal symptoms as an initial presentation of pediatric thyroid storm: report of three cases

OBJECTIVES

Thyroid storm (TS) is a rare but life-threatening condition caused by decompensated hyperthyroidism. There is no consensus on how to diagnose pediatric TS. We report three pediatric cases of TS presenting with central nervous system (CNS) and gastrointestinal (GI) symptoms as the initial presentation of Graves' disease.

CASE PRESENTATION

They were previously healthy adolescents without family history of thyroid disease. CNS symptoms varied from agitation to coma. GI symptoms included abdominal pain, vomiting, and diarrhea. Their laboratory studies revealed thyrotoxicosis and positive result of thyroid-stimulating antibody (TSAb). They were admitted to the intensive care unit (ICU) and received the combination of an antithyroid drug, Lugol's solution, a beta antagonist, and hydrocortisone. The most severe case was a 13 year-old Japanese girl who presented with loss of consciousness and hemodynamic shock. She died after 5 days of intensive treatment.

CONCLUSIONS

Pediatricians should consider TS in the differential diagnosis when a patient exhibits both CNS and GI symptoms.

Extrathyroidal Manifestations of Persistent Sporadic Non-Autoimmune Hyperthyroidism in a 6-Year-Old Boy: A Case Report

Thyroid-stimulating hormone receptor (TSHR) belongs in a subfamily of the G protein-coupled receptors. Thyroid-stimulating hormone receptor gene (TSHR), a gene encoding TSHR, is a major controller of thyroid cell metabolism, and its gain of function mutation leads to non-autoimmune hyperthyroidism (NAH), a condition of a prolonged state of hyperthyroidism. Diverse human diseases, and genetic, constitutional, or environmental factors contribute to the phenotypic variations of TSHR mutations; however, the underlying mechanisms leading to various extrathyroidal manifestations across ages are poorly understood. In 2018, the first Korean case of persistent sporadic NAH due to missense mutation of TSHR was reported, and this report highlights the extrathyroidal manifestations of NAH. Further investigation is warranted to clarify the roles of functional mutations of TSHR by investigating the correlation between G protein-dependent signaling properties and clinical phenotypes associated with persistent hyperthyroidism in order to develop novel therapies that could be provided for numerous conditions caused by NAH.

Effects of glucocorticoid pulse therapy on thyroid function and thyroid antibodies in children with graves' disease

Background

Glucocorticoid treatment is used in children with Graves’ disease (GD) only in cases of exophthalmos. The purpose of this study was to observe the effects of glucocorticoid pulse therapy on thyroid function and thyroid antibodies in children with GD.

Methods

Twenty children who were treated by intravenous methylprednisolone pulse therapy (MPT) followed by oral prednisolone administration and antithyroid drugs were included in the pulse group. Twenty children who were treated with antithyroid drugs alone were included in the control group. Serum concentrations of free triiodothyronine (FT3), free thyroxine (FT4), thyrotropin (TSH), thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TGAb), and thyrotropin receptor antibodies (TRAb) were recorded at baseline and 10 days, 30 days, and 60 days after treatment.

Results

Significant differences in FT3, FT4, TSH, TPOAb, TGAb, and TRAb levels were found in the pulse group and the control group from baseline to follow-up time points (all p < 0.05). On the 30th day, the TRAb level in the pulse group was significantly lower than that in the control group (p = 0.023). However, the level of TRAb rose on the 60th day. For values of TRAb at baseline, 10 days, and 60 days after treatment, there were no significant differences respectively between the pulse group and the control group (all p > 0.05). No significant differences were observed in FT3, FT4, TSH, TPOAb, and TGAb levels between the pulse group and the control group (all p > 0.05).

Conclusions

The results suggested that the effect of intravenous MPT followed by oral prednisolone on TRAb level was temporary in children with GD. Glucocorticoid pulse therapy was not beneficial for the sustained recovery of thyroid function.

Sepsis and thyroid storm in a patient with methimazole-induced agranulocytosis

Paediatric hyperthyroidism cases are mostly caused by Grave's disease. Thyroid storm is a life-threatening condition seen rarely, in severe thyrotoxicosis, occurring in about 1%-2% of patients with hyperthyroidism. Antithyroid medications and beta-blockers are typically the first-line management of thyroid storm. We report a challenging case of a 15-year-old girl who presented with thyroid storm in the setting of septic shock and methimazole-induced agranulocytosis. Since the first-line agents were contraindicated, plasmapheresis was used to control the thyroid storm and as a bridging therapy to the definitive therapy of early thyroidectomy. This is the first paediatric case report that outlines the use of plasmapheresis in the management of complicated thyrotoxicosis in a setting of septic shock.

Surgical treatment of children Graves' disease with huge goiter-a case report and literature review

Graves' disease is the most common cause of hyperthyroidism in children. The surgery treatment for children Graves' disease with huge goiter is high risk and controversial. A 14-year-old girl suffered Graves' disease with huge goiter and failed to the antithyroid drug therapy for nearly 4 years was surgically treated with total thyroidectomy. The excised thyroid weighed 449.1 g and heavier than any excised children goiter reported so far. After operation, the patient's symptoms of Graves' disease were significantly improved without any complication, including normal basal metabolic rate, relieved exophthalmia and euthyroidism. So, a children Graves' disease with huge goiter was cured by total thyroidectomy, suggesting that a total/near-total thyroidectomy is a good option for children Graves' disease with huge goiter.

Thyroid Storm in a Toddler Presenting as a Febrile Seizure

Although simple febrile seizures are relatively common and benign in toddlers, it is important to rule out any underlying critical disease that necessitates further intervention and treatment. Thyroid storm, the extreme manifestation of hyperthyroidism, is relatively rare and not often considered in the differential diagnosis of a febrile seizure despite its high mortality rate. Here, we report 1 of the youngest patients with thyroid storm, who initially presented with a febrile seizure. After reevaluation, the 2-year-9-month-old patient was discovered to have thyromegaly, which led to recognition that her persistent tachycardia and widened pulse pressure were likely signs of thyrotoxicosis. Laboratory results were consistent with primary hyperthyroidism due to Graves' disease. Thyroid storm was then diagnosed on the basis of clinical features including gastrointestinal and central nervous system disturbances. Treatment with methimazole, propranolol, hydrocortisone, and Lugol's iodine solution was used. This medication regimen was safe and effective with restoration of a euthyroid state after 2 months and no recurrence of seizures. Improved awareness of hyperthyroidism and thyroid storm can lead to prompt diagnosis and treatment of this endocrine emergency, thus reducing mortality and morbidity. Pediatricians should consider this diagnosis in children with febrile seizures and suggestive vital signs and physical examination findings.

Management of Thyrotoxicosis in Children and Adolescents: A Turkish Multi-center Experience

OBJECTIVE

To determine the demographic and biochemical features of childhood and juvenile thyrotoxicosis and treatment outcome.

METHODS

We reviewed the records of children from 22 centers in Turkey who were diagnosed with thyrotoxicosis between 2007 to 2017.

RESULTS

A total of 503 children had been diagnosed with thyrotoxicosis at the centers during the study period. Of these, 375 (74.6%) had been diagnosed with Graves’ disease (GD), 75 (14.9%) with hashitoxicosis and 53 (10.5%) with other less common causes of thyrotoxicosis. The most common presenting features in children with GD or hashitoxicosis were tachycardia and/or palpitations, weight loss and excessive sweating. The cumulative remission rate was 17.6% in 370 patients with GD who had received anti-thyroid drugs (ATDs) for initial treatment. The median (range) treatment period was 22.8 (0.3-127) months. No variables predictive of achieving remission were identified. Twenty-seven received second-line treatment because of poor disease control and/or adverse events associated with ATDs. Total thyroidectomy was performed in 17 patients with no recurrence of thyrotoxicosis and all became hypothyroid. Ten patients received radioiodine and six became hypothyroid, one remained hyperthyroid and restarted ATDs and one patient achieved remission. Two patients were lost to follow up.

CONCLUSION

This study has demonstrated that using ATDs is the generally accepted first-line approach and there seems to be low remission rate with ATDs in pediatric GD patients in Turkey.

Neonatal McCune-Albright Syndrome: A Unique Syndromic Profile With an Unfavorable Outcome

Somatic gain‐of‐function mutations of GNAS cause a spectrum of clinical phenotypes, ranging from McCune‐Albright syndrome (MAS) to isolated disease of bone, endocrine glands, and more rarely, other organs. In MAS, a syndrome classically characterized by polyostotic fibrous dysplasia (FD), café‐au‐lait (CAL) skin spots, and precocious puberty, the heterogenity of organ involvement, age of onset, and clinical severity of the disease are thought to reflect the variable size and the random distribution of the mutated cell clone arising from the postzygotic mutation. We report a case of neonatal MAS with hypercortisolism and cholestatic hepatobiliary dysfunction in which bone changes indirectly emanating from the disease genotype, and distinct from FD, led to a fatal outcome. Pulmonary embolism of marrow and bone fragments secondary to rib fractures was the immediate cause of death. Ribs, and all other skeletal segments, were free of changes of typical FD and fractures appeared to be the result of a mild‐to‐moderate degree of osteopenia. The mutated allele was abundant in the adrenal glands and liver, but not in skin, muscle, and fractured ribs, where it could only be demonstrated using a much more sensitive PNA hybridization probe‐based FRET (Förster resonance energy transfer) technique. Histologically, bilateral adrenal hyperplasia and cholestatic disease matched the abundant disease genotype in the adrenals and liver. Based on this case and other sporadic reports, it appears that gain‐of‐function mutations of GNAS underlie a unique syndromic profile in neonates characterized by CAL skin spots, hypercortisolism, hyperthyroidism, hepatic and cardiac dysfunction, and an absence (or latency) of FD, often with a lethal outcome. Taken together, our and previous cases highlight the phenotypic severity and the diagnostic and therapeutic challenges of MAS in neonates. Furthermore, our case specifically points out how secondary bone changes, unrelated to the direct impact of the mutation, may contribute to the unfavorable outcome of very early‐onset MAS. © 2018 The Authors JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

[Correlations of thyroid hormone with deceleration capacity of heart rate and heart rate variability in children with hyperthyroidism]

OBJECTIVE

To investigate deceleration capacity of heart rate (DC), acceleration capacity of heart rate (AC), and heart rate variability (HRV) in children with hyperthyroidism and the correlations of serum thyroid hormone levels with DC, AC, and HRV.

METHODS

A total of 47 children with hyperthyroidism were enrolled as hyperthyroidism group and 50 healthy children were enrolled as control group. The subjects in the two groups underwent 24-hour ambulatory electrocardiography. The two groups were compared in terms of DC, AC, heart rate (HR), HRV parameters [standard deviation of normal-to-normal RR intervals (SDNN), standard deviation of average normal-to-normal RR intervals (SDANN), root mean square of successive differences between adjacent RR intervals (RMSSD), low-frequency power (LF), and high-frequency power (HF)]. The correlations of thyroid hormone indices [free triiodothyronine (FT3) and free thyroxin (FT4)] with DC, AC, and HRV were analyzed.

RESULTS

Compared with the control group, the hyperthyroidism group had significantly lower DC, SDNN, SDANN, RMSSD, LF, and HF and significantly higher AC and HR (P<0.05). In the children with hyperthyroidism, serum FT3 and FT4 levels showed significant negative correlation with DC, SDNN, SDANN, RMSSD, LF, and HF and significant positive correlation with AC and HR (P<0.05).

CONCLUSIONS

Children with hyperthyroidism have cardiac autonomic nerve dysfunction manifested as reduced vagal tone. Vagal tone decreases with the increasing serum thyroid hormone levels, suggesting an increased risk of cardiovascular disease.

Thyroid-stimulating hormone is not the primary regulator of thyroid development in euthyroid children and adolescents living in an iodine-replete area

OBJECTIVES

It is known that there are multiple factors which can affect thyroid gland development during childhood and adolescence. Our aim was to investigate this issue by examining the relationships between age, sex, several anthropometric parameters, pubertal status, thyroid function tests, and iodine intake status with thyroid volume (TV) in children and adolescents.

STUDY DESIGN

This was a cross-sectional field study conducted in 11 representative cities and villages of Uzbekistan. Six hundred and ten children and adolescents participated. Anthropometric indices and TV were estimated. In addition, thyroid function tests (TFTs) and urinary iodine excretion (UIE) measures were obtained.

RESULTS

Median UIE was 151 μg/L, thus the studied areas were iodine-sufficient. TFTs fluctuated in both genders during childhood and adolescence and the thyroid growth spurt was observed, in both sexes, at the ages of 12 and 13 years, which coincided with the age of menarche in girls. Thyroid volume was positively correlated with body surface area (BSA) (r = 0.800, p < 0.001), age (r = 0.780, p < 0.001), fat-free mass (FFM) (r = 0.797, p < 0.001) and negatively correlated with serum TSH (r = -0.154, p = 0.05). No association between thyroid volume and UIE was observed.

CONCLUSIONS

In euthyroid children and adolescents living in iodine-replete areas, thyroid gland development appears to follow the pattern of linear growth and displays a growth spurt at the onset of puberty, probably due to the abrupt increase of circulating sex steroids. At this age, TSH does not appear to be the main regulator of thyroid gland development.

Clinical management of childhood hyperthyroidism with and without Down syndrome: a longitudinal study at a single center

Background The approach to the clinical management of Graves' disease (GD) is debatable. This study aimed to identify predictors of remission in pediatric GD. Methods A longitudinal study of 36 children and adolescents with GD followed from 1997 to 2017 at a single tertiary hospital was performed. Clinical and biochemical parameters, including comorbidities, treatment with anti-thyroid drugs (ATD) or definitive therapy (radioiodine [RIT] and thyroidectomy), and remission as the main outcome were collected. We performed a multivariable logistic regression analysis to identify likely predictors of remission. Results Among patients, most were female, in late puberty, with exuberant symptoms at onset. Eleven also suffered from Down syndrome (DS). Thirty-four patients (94%) started on methimazole from disease onset, and 25 (69%) received it as the only therapy, with a mean duration of 2.7±1.8 years. Six changed to RIT and three underwent thyroidectomy; no DS patient received definitive therapy. Remission was higher in DS patients (45% vs. 25%, p=0.24), but afterwards (3.9±2.5 vs. 2.3±1.4 years, p<0.05); there was no significance in relapsing (20% vs. 15%). Females were less likely to reach remission (p<0.05); serum free thyroxine at onset was higher (p<0.05) in patients who required definitive therapy. Thyroid-stimulating immunoglobulin (TSI) values normalized in exclusively ATD therapy, especially from 2 years on (p<0.05). Conclusions Males were more likely to achieve remission. TSI values may normalize in GD, notably from the second year of treatment. DS children may benefit with conservative management in GD.

Marine-Lenhart syndrome in two adolescents, including one with thyroid cancer: a case series and review of the literature

BACKGROUND

The coexistence of functional thyroid nodules and Graves' disease (GD) is a rare condition known as Marine-Lenhart syndrome. Thyroid cancer has been described in several adults, but never in children, with Marine-Lenhart syndrome. This paper discusses the challenges in diagnosis and the unique management of this condition in children, in the context of extant literature.

CONTENT

In this case report, two adolescent female patients with Marine-Lenhart syndrome, aged 15 and 16 years, exhibited biochemical evidence of hyperthyroidism, and were found to have unilateral hyperfunctioning thyroid nodules via thyroid scintigraphy. Additionally, both patients showed elevated thyroid-stimulating immunoglobulins (TSI) and increased glandular activity, confirming background GD. Notably, one patient was also diagnosed with intranodular thyroid cancer upon preoperative examination. Both patients were treated via surgical resection. Summary and outlook: Diagnosis of Marine-Lenhart syndrome can be made in patients with functional thyroid nodules and increased glandular activity on thyroid scintigraphy. Standard doses of radioiodine ablation are not effective in the majority of patients and should be avoided due to the increased risk for thyroid cancer, making thyroidectomy the preferred treatment.

Autoimmune thyroid diseases in children

Autoimmune thyroid diseases (AIT) are common in children and may present with a variety of signs and symptoms including: euthyroid goiter, hypothyroidism, or hyperthyroidism. The natural history of AIT may be different in children but in all age groups, there appear to be genetic risk factors and environmental triggers that initiate thyroid autoimmunity. Areas covered: In this review, we summarize recent studies that investigate the genetics and environmental triggers believed to be involved in thyroid autoimmunity. We also discuss the approach and controversies in the treatment of children with AIT. Expert commentary: Much has been learned about the major roles for genetics, cytokines, regulatory lymphocytes, and environmental triggers in CLT but controversies remain.

Neurological Complications of Endocrine Disease

The endocrine system is a complex group of organs and glands that relates to multiple other organs and systems in the body with the ultimate goal of maintaining homeostasis. This complex network functions through hormones excreted by several glands and released in the blood, targeting different body tissues and modulating their function. Any primary disorders affecting the endocrine glands and altering the amount of hormones synthesized and released will lead to disruption in the functions of multiple organs. The central nervous system of a developing child is particularly sensitive to endocrine disorders. A variety of neurological manifestations have been described as features of several endocrine diseases in childhood. Their knowledge may contribute to an early diagnosis of a particular endocrine condition, especially when more typical features are not present yet. In this article, we discuss specific neurological manifestations found in various endocrine disorders in children.