Hyperthyroidism

Definition

Hyperthyroidism in children is a condition characterized by excessive production of thyroid hormones, leading to accelerated metabolism, growth acceleration, and multiple systemic effects.

Epidemiology

• Less common in children than adults
• Peak incidence in adolescence
• More common in females than males
• Graves’ disease is the most frequent cause in children
• Incidence varies geographically and with iodine intake

Etiology

• Graves’ disease (autoimmune thyroid-stimulating antibodies)
• Toxic multinodular goiter (rare in children)
• Thyroid adenoma
• Subacute thyroiditis
• Excessive intake of thyroid hormone
• Genetic syndromes associated with thyroid dysfunction (rare)

Pathophysiology

• Excess thyroid hormones (T3 and T4) increase basal metabolic rate
• Enhanced adrenergic activity causes tachycardia, tremors, and hyperactivity
• Accelerated bone turnover may lead to advanced bone age
• Increased hepatic metabolism leads to elevated liver enzymes
• Cardiac output increases, potentially causing cardiomegaly or arrhythmias
• Autoimmune stimulation in Graves’ disease leads to diffuse goiter and ophthalmopathy