Severe hyperthyroidism without symptoms due to nonthyroidal illness in a child with acute hepatitis: case report and...

Area of Science:

• Endocrinology
• Hepatology
• Pediatrics

Background:

• Liver dysfunction can impact thyroid hormone metabolism, but the precise relationship with hyperthyroidism remains unclear.
• Hyperthyroidism, characterized by elevated thyroid hormones, can manifest with liver enzyme changes, yet direct liver dysfunction is less understood.
• Understanding the interplay between thyroid disorders and liver health is crucial for comprehensive patient care.

Observation:

• An 11-year-old boy presented with acute hepatitis of unknown origin and was incidentally found to have biochemical hyperthyroidism.
• The patient exhibited elevated total and free thyroxine (T4) levels but lacked clinical signs of thyrotoxicosis.
• Reduced thyroid I-123 uptake, slight triiodothyronine (T3) elevation, and significant reverse T3 (rT3) elevation were noted.

Findings:

• Initial tests for Graves' and Hashimoto's thyroiditis were negative, leading to a hypothesis of transient thyroiditis, possibly linked to an undiagnosed infectious etiology.
• Subsequent positive thyroid peroxidase antibodies indicated autoimmune Hashimoto's thyroiditis as the probable cause of hyperthyroidism.
• The absence of thyrotoxicosis symptoms was attributed to a concurrent nonthyroidal illness, explaining the specific thyroid hormone profile (elevated T4, T3, and rT3).

Implications:

• This case underscores the importance of considering thyroid dysfunction in pediatric patients with unexplained hepatitis.
• Biochemical hyperthyroidism can occur asymptomatically, particularly in the context of other severe illnesses.
• The findings suggest that nonthyroidal illness can significantly alter thyroid hormone levels and mask clinical presentation, necessitating thorough diagnostic evaluation.