I was first diagnosed with GD in 1992 via biopsy. Had no itch until 2007 when, after 18 months of misery, a new derm prescribed Gabapentin which worked for 13 years. It stopped working about 18 month ago and I'm using Eucerin Itch Relief when it's bad and Hydroxyzine at night to sleep. Eucerin Calming Body Wash might be helping a little, it's hard to tell. Just started Cilantro capsules a couple days ago and today ordered some Chlorella capsules.
In 2007 on a forum called Skincell, people used to talk about mercury and getting your old fillings removed. I thought that was a bit extreme and never considered it and still went into remission for the 13 years.