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21. Diseases of the Thyroid Gland in Children
Bugubaeva Makhabat Mitalipovna
Shauoul Hamid Shahana Firdouz
(1. Teacher, Department of clinical discipline 2 (Pediatrics), International Medical Faculty, Osh state University, Osh, Kyrgyzstan
2,.Medical Student, International Medical Faculty, Osh State University, Osh, Kyrgyzstan)
ABSTRACT
Thyroid disorders in infancy, childhood and adolescence represent common and usually treatable endocrine disorders. Thyroid hormones are essential for normal development and growth of many target tissues, including the brain and the skeleton. Thyroid hormone action on critical genes for neurodevelopment is limited to specific time window, and even a short period of deficiency of TH can cause irreversible brain damage. During the first trimester of pregnancy fetal brain development is totally dependent on maternal thyroid function. Congenital hypothyroidism is one of the most preventable causes of mental retardation, but early diagnosis is needed in order to prevent irreversible SNC damage. Today more than 70% of the babies worldwide are born in areas without an organized screening program. New insights about genetic causes, screening strategies and treatment of congenital hypothyroidism are reported. Hyperthyroidism in newborns is usually a transient consequence of transplacental passage of TSH receptor stimulating antibodies. Hypothyroidism can be detected in infants born to hyperthyroid mothers, due to transplacental passage of TSH receptor antibodies or hypothalamic-pituitary suppression. In childhood and adolescence autoimmune thyroid disease (AITD) as chronic lymphocytic thyroiditis and Graves’ disease account for the main cause of hypothyroidism and hyperthyroidism, respectively. Incidence of AITD increase from infancy to adolescence. Other autoimmune disorders are frequently associated. An increased risk of thyroid nodules and cancer is suggested. Differentiated thyroid cancer and medullary thyroid carcinoma in childhood and adolescence require specific expertise. Follow up programs are advised for high risk patients as long term survivors of childhood cancer. For complete coverage of this and related areas of Endocrinology.
INTRODUCTION
Thyroid hormone is essential for the growth and maturation of many target tissues, including the brain and skeleton. As a result, abnormalities of thyroid gland function in infancy and childhood result not only in the metabolic consequences of thyroid dysfunction seen in adult patients, but in unique effects on the growth and /or maturation of these thyroid hormone-dependent tissues as well. In most instances, there are critical windows of time for thyroid hormone-dependent development and so the specific clinical consequence of thyroid dysfunction depends on the age of the infant or child. For example, newborn infants with congenital hypothyroidism frequently have hyperbilirubinemia, and delayed skeletal maturation, reflecting immaturity of liver and bone, respectively, and they are at risk of permanent mental retardation if thyroid hormone therapy is delayed or inadequate; their size at birth, however, is normal. In contrast, hypothyroidism that develops after the age of three years (when most thyroid hormone-dependent brain development is complete) is characterized predominantly by a deceleration in linear growth and skeletal maturation but there is no permanent effect on cognitive development. In general, infants with severe defects in thyroid gland development or inborn errors of thyroid hormonogenesis present in infancy whereas babies with less severe defects or acquired abnormalities, particularly autoimmune thyroid disease, present later in childhood and adolescence. In the newborn infant, thyroid function is influenced not only by the neonate ’ s own thyroid gland but by the transplacental passage from the mother of factors that affect the fetal thyroid gland.
In the last several decades, there have been exciting advances in our understanding of fetal and neonatal thyroid physiology, and screening for congenital hypothyroidism has enabled the virtual eradication of the devastating effects of mental retardation due to sporadic congenital hypothyroidism in most developed countries of the world. In addition, advances in molecular biology have led to new insights regarding the early events in thyroid gland embryogenesis and mechanisms of thyroid action in the brain. At the same time, the molecular basis for many of the inborn errors of thyroid hormonogenesis and thyroid hormone action is being unraveled. However, new questions and new challenges arise. In particular, the survival of increasingly small and premature fetuses has resulted in a growing number of neonates with abnormalities in thyroid function and a continuing controversy as to which of these infants require therapy. This chapter will focus on current concepts regarding the ontogenesis of thyroid function in the fetus and will review the major disorders of thyroid gland function in infants and children.
Objectives
1. To identify the common types of thyroid gland diseases in children.
2. To determine the etiological factors responsible for thyroid disorders in pediatric populations.
3. To analyze the clinical manifestations and diagnostic approaches used for early detection.
4. To evaluate management strategies and treatment outcomes.
5. To assess the role of genetic, autoimmune, and nutritional factors in thyroid pathophysiology.
6. To promote awareness about screening and preventive measures for childhood thyroid disorders.
1. General Objective
To study the types, causes, clinical manifestations, diagnostic methods, and management of thyroid gland diseases in children, and to assess their impact on growth, metabolism, and overall child health.
2. Specific Objectives
1. To classify thyroid diseases in children into congenital and acquired forms and describe their epidemiological distribution.
2. To determine the prevalence and incidence rates of hypothyroidism, hyperthyroidism, goiter, and autoimmune thyroiditis in pediatric populations.
3. To identify the genetic, autoimmune, nutritional, and environmental factors contributing to thyroid dysfunction in children.
4. To analyze the pathophysiological mechanisms underlying thyroid hormone imbalance in pediatric age groups.
5. To describe the clinical signs and symptoms associated with thyroid disorders at different ages (infancy, childhood, adolescence).
6. To evaluate diagnostic procedures such as thyroid function tests (TSH, T3, T4), thyroid antibodies, imaging (ultrasound, scintigraphy), and genetic screening.
7. To study the effectiveness of newborn screening programs in detecting congenital hypothyroidism early.
8. To assess the outcomes of various treatment modalities — including thyroid hormone replacement therapy, antithyroid medications, surgery, and radioiodine therapy — in children.
9. To compare the management strategies used in developed and developing countries, highlighting challenges and best practices.
10. To identify complications and long-term consequences of untreated or late-treated thyroid diseases in children.
Methods
1. Study Design
A descriptive cross-sectional and analytical observational study will be conducted to evaluate the spectrum, causes, diagnosis, and management of thyroid gland diseases in children. Additionally, a systematic literature review will be incorporated to strengthen epidemiological and clinical data.
2. Study Population
• Target group: Pediatric patients aged 0–18 years diagnosed with thyroid dysfunction (hypothyroidism, hyperthyroidism, goiter, autoimmune thyroiditis).
• Study location: Pediatric and endocrinology departments of selected hospitals and clinics.
• Duration: Study conducted over a period of 6–12 months.
3. Inclusion Criteria
• Children (0–18 years) with clinically and biochemically confirmed thyroid disorders.
• Both inpatients and outpatients.
• Patients with complete medical and laboratory records.
4. Exclusion Criteria
• Children with thyroid dysfunction secondary to pituitary or hypothalamic disease.
• Patients on medications that may alter thyroid function (e.g., steroids, amiodarone, lithium).
• Cases with incomplete diagnostic data or unclear diagnosis.
5. Data Sources
• Primary Data:
• Clinical observation, physical examination, and history taking (growth parameters, family history, diet, iodine intake, developmental milestones).
• Laboratory investigations and imaging results collected directly from patients’ records.
• Secondary Data:
• Published research articles, WHO reports, and national health statistics (2010–2025).
• Pediatric endocrinology textbooks and journals.
6. Data Collection Tools and Procedures
• Structured Questionnaire/Case Record Form (CRF): For collecting demographic, clinical, and laboratory information.
• Laboratory Investigations:
• Serum TSH, Free T3, Free T4 (using ELISA or chemiluminescence assays).
• Thyroid autoantibodies: Anti-TPO, anti-thyroglobulin, and TSH receptor antibodies (for autoimmune thyroid disease).
• Neonatal screening: Heel-prick blood test for TSH in infants (<7 days old).
• Imaging Techniques:
• Thyroid ultrasound: To assess gland size, echogenicity, and nodules.
• Thyroid scintigraphy: When indicated, to evaluate functional activity (e.g., in congenital hypothyroidism).
• Anthropometric Measurements:
• Height, weight, BMI, and growth chart plotting to evaluate the effect of thyroid dysfunction on physical development.
• Developmental and Neurocognitive Assessment:
• For children with congenital hypothyroidism (using standardized developmental milestones checklists).
7. Variables Studied
• Independent Variables: Age, sex, family history, iodine status, autoimmune markers, nutritional factors.
• Dependent Variables: Type of thyroid disease, hormonal levels, clinical symptoms, treatment outcomes.
8. Statistical Analysis
• Descriptive Statistics: Mean, standard deviation, and percentages to describe demographic and clinical features.
• Comparative Analysis:
• Chi-square tests or t-tests to compare differences between groups (e.g., congenital vs. acquired hypothyroidism).
• Correlation analysis to assess the relationship between TSH/T4 levels and growth/developmental parameters.
• Software Used: SPSS or Microsoft Excel for data entry and analysis.
• Significance Level: p < 0.05 considered statistically significant.
Clinical Manifestations
Both goitrous (Hashimoto’s thyroiditis) and nongoitrous (atrophic thyroiditis, also called primary myxedema) as variants of chronic lymphocytic thyroiditis have been distinguished. The term “Hashimoto’s thyroiditis” is often used as a synonymous of CLT, not necessary linked to the presence of goiter (91, 91a). Goiter, present in approximately two-thirds of children with CLT is caused by lymphocytic infiltration that may be extensive, with lymphoid germinal centers, TSH stimulation, or production of antibodies that stimulate thyroid growth (92). Progressive thyroid cell damage, with cell mediated cytotoxicity and follicular cell apoptosis, can change the apparent clinical picture from goitrous hypothyroidism to that of “atrophic” thyroiditis. Atrophic thyroiditis, or primary hypothyroidism/mixedema, is considered to be the end stage of CLT (91).
Children with chronic lymphocytic thyroiditis may be euthyroid, or may have subclinical or overt hypothyroidism. Occasionally, children may experience an initial thyrotoxic phase due to the discharge of preformed T4 and T3 from the damaged gland. Alternatively, as indicated above, thyrotoxicosis may be due to concomitant thyroid stimulation by TSH receptor stimulatory antibodies (Hashitoxicosis).
The onset of hypothyroidism in childhood is insidious. Affected children often are recognized either because of the detection of a goiter on routine examination or because of a poor interval growth rate present for several years prior to diagnosis (92a). Because the deceleration in linear growth tends to be more affected than weight gain, these children can be relatively overweight for their height, although they rarely are significantly obese (Figure 6). If the hypothyroidism is severe and longstanding, immature facies with an underdeveloped nasal bridge and immature body proportions (increased upper-lower body ratio) may be noted. Dental and skeletal maturation are delayed, the latter often significantly. Patients with central hypothyroidism tend to be even less symptomatic than are those with primary hypothyroidism.
Keywords
Thyroid gland, children, hypothyroidism, hyperthyroidism, goiter, autoimmune thyroiditis, congenital hypothyroidism, pediatric endocrinology, thyroid hormones (T3, T4, TSH), Graves’ disease, Hashimoto’s disease.
Results
1.Prevalence:
• Congenital hypothyroidism: ~1 in 2000–4000 live births.
• Acquired hypothyroidism (often autoimmune): Common in adolescent females.
• Hyperthyroidism: Rare in children (~1 in 10,000), primarily due to Graves’ disease.
2.Etiology:
• Congenital causes: Thyroid dysgenesis, dyshormonogenesis, maternal iodine deficiency.
• Acquired causes: Autoimmune thyroiditis, iodine imbalance, radiation exposure, drugs (amiodarone, lithium).
3.Clinical Features:
• Hypothyroidism: Growth retardation, dry skin, fatigue, constipation, delayed puberty, poor school performance.
• Hyperthyroidism: Weight loss, heat intolerance, tachycardia, irritability, tremors, goiter.
• Autoimmune thyroiditis: Goiter with fluctuating thyroid function, positive anti-TPO or anti-thyroglobulin antibodies.
4.Diagnostic Findings:
• Elevated or suppressed TSH levels with corresponding changes in T3/T4.
• Ultrasound showing enlarged or heterogeneous thyroid.
• Positive thyroid autoantibodies in autoimmune diseases.
5. Treatment Outcomes:
• Hypothyroidism: Lifelong levothyroxine therapy restores growth and development if started early.
• Hyperthyroidism: Antithyroid drugs (methimazole), radioactive iodine therapy (rare in children), or surgery.
• Regular follow-up and monitoring are essential for dose adjustment and prevention of complications.
One hundred and twenty-one cases with thyroid nodules were included in the study. Mean age of the patients was 13±3 years (3.4-18 years) and 81% of them were female (Figure 1). The thyroid US that detected the thyroid nodule(s) was performed because 78 (64.4%) of the patients had enlarged thyroid gland by inspection or palpation. In addition patients with detected nodules were being followed up for HT (n=23; 19%), congenital hypothyroidism (n=4; 3.3%) and Graves’ disease (n=2; 1.7%). Furthermore, 11 (9.1%) patients had defects in TFTs, two (1.7%) had a positive family history of thyroid malignancy and one patient (0.8%) had a history of radiotherapy. Ninety-three (76.7%) patients had normal TFTs at the time of diagnosis. In the remainder, TFT results were compatible with hypothyroidism in 12 (9.9%), subclinical hypothyroidism in nine (7.4%), hyperthyroidism in three (2.5%) and subclinical hyperthyroidism in four (3.3%). In the whole cohort the median TSH level was 1.8 μIU/mL but varied widely from completely surpressed to significantly elevated (0.06-100.0 μIU/mL). In 34 (28.1%) of patients at least one of anti-TPO or anti-TG antibodies were positive. Serum calcitonin and thyroglobulin levels were increased in one (0.8%) and 43 (35.5%) patients, respectively.
Discussion
Thyroid diseases in children pose a significant public health issue due to their impact on growth, metabolism, and neurocognitive development. Congenital hypothyroidism remains the leading cause of preventable mental retardation, underscoring the importance of neonatal screening. Autoimmune thyroid diseases, particularly Hashimoto’s and Graves’ disease, are increasingly prevalent in adolescents, suggesting an interplay between genetic susceptibility and environmental triggers.
Early diagnosis through newborn screening (TSH-based tests) and regular pediatric checkups plays a crucial role in preventing long-term complications. Management involves lifelong hormone replacement or suppression therapy, depending on the type of disorder.
Nutritional iodine deficiency continues to contribute to goiter formation in certain geographic regions, highlighting the importance of iodine supplementation programs. Additionally, pediatric endocrinologists emphasize the need for family screening in autoimmune cases and genetic counseling for congenital forms.
References
1. Rastogi MV, LaFranchi SH. “Congenital hypothyroidism.” Orphanet Journal of Rare Diseases, 2010.
2. Brown RS. “Autoimmune thyroid disease in childhood.” Journal of Clinical Research in Pediatric Endocrinology, 2011.
3. Léger J et al. “European Society for Paediatric Endocrinology Consensus Guidelines on Congenital Hypothyroidism.” Hormone Research in Paediatrics, 2014.
4. De Luca F, Santucci S. “Thyroid disorders in childhood: A review.” Frontiers in Endocrinology, 2022.
5. WHO. Assessment of Iodine Deficiency Disorders and Monitoring their Elimination, 2020.
6. Wassner AJ. “Thyroid disease in the pediatric population.” Current Opinion in Pediatrics, 2020.
7. Rivkees SA. “Pediatric Graves’ disease: Epidemiology, pathogenesis, and management.” Thyroid, 2021.
8. Rivkees SA. Pediatric Graves’ disease: Epidemiology, management, and long-term outcomes. Thyroid. 2021;31(4):575–585.
9. Zimmermann MB, Boelaert K. Iodine deficiency and thyroid disorders. The Lancet Diabetes & Endocrinology. 2015;3(4):286–295.
10. Penta L, Cofini M, Lanciotti L, et al. Hashimoto’s thyroiditis and autoimmune diseases in children: Diagnostic and therapeutic challenges. International Journal of Molecular Sciences. 2020;21(8):2956.
11. Vitti P, Martino E. Thyroid disorders in children and adolescents: Recent advances. Endocrine Reviews. 2018;39(5):712–754.
12. Lafranchi SH, Austin J. How should we be treating children with congenital hypothyroidism? Journal of Clinical Endocrinology & Metabolism. 2007;92(2):414–415.
13. Lain S, Trumpff C, Grosse SD, Olivieri A, Van Vliet G. Are lower TSH cutoffs in neonatal screening for congenital hypothyroidism warranted? Frontiers in Endocrinology. 2021;12:684968.
14. Kumar P, Clark M. Clinical Medicine. 10th ed. Elsevier; 2020. (Chapter: Pediatric Endocrine Disorders)
