|I have the same thing. I know it is in the same exact spot because I have SCARS outlining the area. The time is about the same as well, 2-3 months. It first happened on my wrist and finger, recurred 2 or 3 times, and hasn't in a year or two. This summer I got it really bad on my legs, enough to require steroids and it scarred. It's been about 2 months and it has recurred.
For me, the recurring rashes are a little different. No papules, more little red bumps. I'm not sure what triggers it or what is going on (over reactive mast cells, hypersensatized skin) but it is definitely NOT re-exposure to clothes,etc. or urushiol oil sequestered in my skin.
I guess I'm hoping that it will gradually stop happening. It stopped happening in the first location so hopefully the second will be the same. I can't think of any treatment that would be worth it, just grin and bear it.