The Wolff-Chaikoff effect refers to a transient decrease in thyroid hormone production following administration of an excess of iodine.
Possible mechanisms:
(1) temporary downregulation of the sodium iodide transporter in the thyroid
(2) inhibition of thyroid peroxidase activity
Clinical features:
(1) transient decrease in thyroid hormone production following administration of iodine
(2) return to basal state within 48 hours
(3) it may occur in patients with a normal thyroid gland or a patient with thyroid disease
Hypothyroidism may occur in patients with a pre-existing thyroid disorder.
Sources of excess iodine:
(1) iodinated contrast media for an imaging study
(2) oral iodine supplement
(3) exposure to iodinated antiseptic solutions
