Ohmycrap, you guys! I have this and had no idea it was a *thing* till I saw this thread. It's possible I haven't had it for that long. I just noticed it in my pits in the last year (maybe even six months) and I have these rough grayish patches on my right elbow and right ankle (kinda like these, but fairly light, I guess:
http://www.3fatchicks.com/forum/pcos...ns-fading.html ).
I'm not really sure about the ankle and elbow patches because aside from being a darkish gray (not DARK gray, but dark compared to my skin tone and gray), they are super rough and sometimes they itch like mad. I thought they were just age-related (I'm 40). And they seem to get a little better if I consistently rub oil into them. Hmmmm....
I definitely have to ask the endo next time I see him. I am so surprised because a quick google search says it's from too much insulin. I am a type I diabetic, so my body doesn't produce any insulin, I get it all from a bottle. For many years, before I got back into low carbing, I was doing somewhere around 100 units a day, but now that I've cut out almost all carbs I'm always under 20 and often down around 14 units a day, which I think is super low. And I've been doing this for about 4 months now, so it seems like it should be getting better.
Anyhow, OP, I don't know when it'll go away in relation to weight. Since I've just lost almost 40 pounds, I keep having to remind myself I'm not a skinny waif and still have 60 to go. I feel nearly normal weighted, though I know I'm not, my bmi is till in the mid-30s. Gah!