I am getting my right arm sleeve finished off, and it is such a large area that the itching is driving me nuts. I just started trying Beauty Brew Tattoo Aftercare, and it helps with the itching a lot. It's pretty natural stuff, which I like, and it is really great to not have nonstop itching. If you haven't tried it, give it a go.
(By the way, this isn't an ad—another heavily tattooed guy recommended it, and it rules. I paid for it like every one else, but I love it and wanted to tell you guys about it.)