This occurred at the same time that my thyroid numbers improved really making me think that one theory made the most sense, at least in my case: (bjjcaveman.com)
I have Hashimotos but I am iodine deficient and my Dr put me on Iodoral it has 5 mg of iodine and 7.5 mg of iodine (as potassium salt) I take 2 pills and it has helped bring my thyroid numbers in normal range. (floliving.com)