What is meant by Wolff-Chaikoff effect?
The Wolff-Chaikoff effect is an effective means of rejecting the large quantities of iodide and therefore preventing the thyroid from synthesizing large quantities of thyroid hormones.
What is the Jod-Basedow phenomenon?
Jod-Basedow phenomenon occurs due to either overactivation of the entire thyroid gland or, more commonly, autonomous nodules within the gland after iodine repletion without adequate feedback control from the pituitary gland. This escape from the protective Wolff-Chaikoff effect is called the Jod-Basedow phenomenon.
How long does Jod-Basedow phenomenon last?
This phenomenon is known by the name of the Wolff-Chaikoff effect and is thought to be caused by a temporary downregulation of the sodium iodide transporter in the thyroid. Most patients can return to a euthyroid state within 24 to 48 hours.
What is thyroid escape phenomenon?
“Escape phenomenon” is believed to occur because of decreased inorganic iodine concentration inside the thyroid follicle below a critical threshold secondary to down-regulation of sodium-iodide symporter (NIS) on the basolateral membrane of the thyroid follicular cell.
Why is iodine used to treat hyperthyroidism?
Radioactive iodine is taken up by the thyroid, and destroys the cells in the thyroid gland. This has the effect of reducing the amount of thyroxine made by the thyroid gland and may also reduce the size of the gland.
Why does iodine cause hypothyroidism?
HYPOTHYROIDISM – As the body’s iodine levels fall, hypothyroidism may develop, since iodine is essential for making thyroid hormone. While this is uncommon in the United States, iodine deficiency is the most common cause of hypothyroidism worldwide (see Hypothyroidism brochure).
What is Pretibial myxedema?
Pretibial myxedema (also called localized myxedema, thyroid dermopathy, or infiltrative dermopathy) is an infrequent manifestation of Graves’ disease. It forms the third component of the classical triad of Graves’ disease (goiter, orbitopathy, and pretibial myxedema).
Why does iodine inhibit thyroid release?
Iodine and Iodine-Containing Compounds Inorganic iodine given in pharmacologic doses (as Lugol’s solution or as saturated solution of potassium iodide [SSKI]) decreases its own transport into the thyroid, inhibits iodine organification (the Wolff-Chaikoff effect), and blocks the release of T4 and T3.
How long does iodine induced hyperthyroidism?
Iodine excess inhibits iodide accumulation, organogenesis, tyrosine binding, and thyroid hormone release. However, this inhibitory effect (Wolff-Chaikoff effect) lasts only 10–14 days, followed by the so-called escape phenomenon [6].
Can iodine induced hypothyroidism be reversed?
In conclusion, hypothyroidism observed in patients with high 99mTc uptake and non-hormonal iodine levels and undetectable or low titers of TgAb and TPOAb can be reversed, and we recommend starting thyroid hormone replacement therapy in those who are considered to have advanced Hashimoto’s thyroiditis and history of …
What is aldosterone escape phenomenon?
Aldosterone escape is a physiologic phenomenon that occurs with hyperaldosteronism. Aldosterone initially decreases urinary sodium increasing sodium retension contributing to hypertension. This does not result in edema because the sodium retention is short lived.
What are the symptoms of too much iodine in your body?
High iodine intakes can also cause thyroid gland inflammation and thyroid cancer. Getting a very large dose of iodine (several grams, for example) can cause burning of the mouth, throat, and stomach; fever; stomach pain; nausea; vomiting; diarrhea; weak pulse; and coma.
What does pretibial myxedema look like?
It usually presents itself as a waxy, discolored induration of the skin—classically described as having a so-called peau d’orange (orange peel) appearance—on the anterior aspect of the lower legs, spreading to the dorsum of the feet, or as a non-localised, non-pitting edema of the skin in the same areas.
What is the difference between pretibial myxedema and myxedema?
Generalized myxedema is associated with only the hypothyroid state, whereas pretibial myxedema is characteristically associated with Graves’ disease. Patients with pretibial myxedema may be hypothyroid, hyperthyroid, or euthyroid when the skin disorder appears.
Does iodine cause hyper or hypothyroidism?
Excess iodine intake is considered to be associated with hyperthyroidism or hypothyroidism in some vulnerable individuals [5, 6]. Iodine-induced hyperthyroidism (IIH) has been reported as a side effect of iodine supplementation. This is also called as “Jod-Basedow phenomenon”.