I had a similar experience when starting Iodine supps, not so much itchy, but tingly. People have also had similar sensations in their thyroid after starting Iodine supps.
Looking back I can now see that this 'boob' sensation was the Iodine working on the FBD that I had. I believe it was the iodine increasing apoptosis, (programmed cell death), in the breast tissue.
I now have no FBD whatsoever, no fibroids, no hypothyroidism, no anaemia etc etc, and that gives me a whole new tingly feeling :)