I'm not as sensitive as the OP, and I'm not totally sure for me if it's the carbs or the salt or the combination. Before primal, I rarely used table salt because I was eating enough deli meats/cheeses, condiments, canned soups, etc., that I knew I was getting plenty of sodium from them.
Now I do use salt, but probably not as much as a lot of folks, mostly because I don't have much of a taste for it. The exception is rice/white potatoes. When I put either in a dish or eat one as a late night snack, I tend to salt it a lot. Then I wake up with swollen fingers. Since that's the only thing that does it now, I'm not sure which causes the puff.
OP, it sounds like you're very sensitive. I might ask my doc about it at your next appointment. It might be as simple as being low in potassium, or something that needs attention.
"Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine