RAI is pretty hard on the whole body. May radiologist will say that is does not travel through the body and the thyroid only absorbs the I131 Iodine - but that is really not the case.
Were you told to drink lots of water after you took the RAI? I wasn't and body, reaced very badly to the pill.
I have a similiar experience with RAI as you did. A rash IS very common with RAI - due to the levels of iodine in this. I can't say for sure about the knots forming but in my case, my lymph nodes absorb the RAI and actually were burnt (scared) so I now have permanent enlargement.
In order to have them shink I started iodine therapy. This is not the same as RAI and I don't believe you would be a candidate for this right now.
It was 4 years after RAI - that my body returned to some normalcy to start treatment correctly.
Hi and WELCOME to our Community --- I'm not well versed with your ? about this type of reaction but wanted to stop by and say hi!~
WELCOME! C~