parasite cleansing will up the amount of Iodine you can use because of less dieoff.
Are you dealing with a chronic illness related to a fungal infection, (use boron/borax water for 1-2 months first, it's a cofactor. )
or ever been treated for Depression or mental-illness related symptoms? (Use salt-loading, boron and fat-soluable vitamins together with selenium. Use at least 2 months on selenum at 300-600 mg to see if you have adverse reactions, then push up on the iodine. (all of those listed are cofactors))
Kickback (detox) is different from person to person depending upon the status of their health, age, and toxic load.
There is one way to see what the story is though. If you've grabbed a bottle of Lugol's or SSKI (super-saturated potassium iodide), put the dose you're thinking of taking orally into your bellybutton while laying on your back on your bed, and observe the results.
if your heartbeat picks up intensely (5-10 mins post-application) and your thyroid starts to tighten (the area around your throat)(10-15 mins after application), you've got very absorbant skin and need a lot of fatty-soluable vitamins. That's leaky skin. Leaky skin's more or less like leaky gut, membrane permeability's gone pretty loose, it's likely a fungal infection (candida) and an herbal parasite cleanse would be of benefit.
If your skin is quite oily and water-resistant, and the symptoms show up slower, try your oral dose. I still caution to have all the cofactors at home...!!
Oily skin btw indicates taking a bit more zinc.