[Iodine excess and iatrogenic thyroid pathology (author's transl)]

Area of Science:

• Endocrinology
• Thyroidology

Context:

• Iodine is essential for thyroid hormone synthesis but excess intake can lead to thyroid dysfunction.
• Amiodarone is a common cause of iodine-induced hypothyroidism and hyperthyroidism.
• Premature infants exhibit heightened sensitivity to iodine exposure.

Purpose:

• To review the mechanisms, clinical features, and management of iodine-induced thyroid disorders.
• To highlight the diagnostic criteria and therapeutic options for iodine-induced hypothyroidism and hyperthyroidism.

Summary:

• Iodine-induced hypothyroidism, often diagnosed via the Perchlorate discharge test, may involve impaired thyroglobulin proteolysis.
• Iodine-induced hyperthyroidism, prevalent in males with prior normal thyroids, is characterized by increased 131I uptake and spontaneous resolution, though treatment may be necessary.
• Therapeutic options for severe cases include corticoids and propylthiouracil (PTU), though PTU's efficacy is variable.

Impact:

• Understanding iodine's dual role in thyroid health is crucial for clinical practice.
• This review provides insights into managing a common yet complex endocrine disorder.
• Identifying potential common pathogenic mechanisms may guide future research and therapeutic strategies.