Iodine Patch Test -- reflections by Dr Jack Kessler

[Guest guest]

Since Dr Kessler knows a lot about the biochemistry of iodine, I asked him for his thoughts on the validity of the patch test.

Zoe: Based upon what you know about transdermal absorption, could the iodine patch test have any validity at all?

Dr Kessler: When you ask me to step over into the clinical domain it gets much more difficult. First off, I’d like to see an experiment that actually measures an increase in total serum iodine (all forms, T3, T4, iodide, …..). I don’t think we would be able to measure it. At this time, there is no objective data that suggests the patch test is indicative of anything. Could enough iodine be absorbed? I really doubt it. When nurses are swabbed with iodine on a continuing basis chronically there are slight alterations in their thyroid hormone status. This suggests that iodine is being absorbed but not to a significant extent.

I need to see controlled data before I would believe there is any utility. At this time no such data exists. If forced to speculate I think the test has absolutely no validity. To suggest that the uptake of iodine in skin is a measure of the iodine status is just extremely unrealistic bordering on delusional. The loss of “color” is not due to the reduction of I2 but to evaporation and absorption. Gottardi’s manuscript will interest you.

Zoe: Is it conceivable that total body stores of iodine could affect how fast the iodine on the skin disappears??? Since iodine is in the skin, could it operate on a local level?

Dr Kessler: It is inconceivable to me. I would not believe it until I saw data supporting it. I’ll look in Iyengar to see if someone has measured the concentration of iodine in skin and get back to you.

Zoe