Yes, your thumb pain is related to the iodine. For me, it started back in March/Feb? with the beginning of Iodine supplementation. I had it first in the left thumb, then in the right & left thumb, and now mainly in the right thumb. It is worse if I microdose (1/2 drop per week) and it's worse the first day or so after I take my dose. The left thumb heals almost entirely between my doses and the right thumb changes but doesn't get better.
I think the salt Water Cure may help but it also seems to bloat me so I only do it occasionally.
I am now doing 5 drops once a week(ever since my hubby unwittingly dosed me with a lot of iodine). I take no Iodine the rest of the week and the symptoms gradually get better. I am experimenting with quantity and timing so that my thumb (right) doesn't get too sore to work & I don't get too irritable with my family.
I feel that the Iodine is releasing poisons that we need to detox.
My energy levels are better, I need much less sleep, I'm more awake mentally. I definately will continue Iodine.