Jod-Basedow Phenomenon (or Syndrome) is an episode of hyperthyroidism that follows an exposure to excess iodine.
Risk factors:
(1) nontoxic diffuse or nodular goiter
(2) latent Graves' disease
(3) long-standing iodine deficiency
(4) thyroiditis (Hashimoto's, autoimmune, other)
(5) chronic kidney disease or end-stage renal disease (impaired excretion of iodine)
Clinical features:
(1) exposure to excess of iodine
(2) quiescent thyroid tissue becomes hyperfunctioning
(3) subsequent hyperthyroidism/thyrotoxicosis
Sources of excess iodine:
(1) iodinated contrast media for an imaging study
(2) oral iodine supplement
(3) exposure to iodinated antiseptic solutions