In reply to McHeath:
I have it on my elbows (and previously on one leg) and even there it's unpleasant, itchy, irritating and embarrassing. Thankfully I'm lucky enough that it doesn't affect my ability to do stuff because of where it's located so you have my absolute sympathy.
Wrt treatment, I manage mine purely with loads of Hydramol and by using a soft brush when I'm in the shower/bath and that keeps the itchiness and flakiness to a minimum. I've tried steroid cream, which works amazingly for a week or so but the plaques just return as soon as I stop so I decided it wasn't worth the negative aspects of steroid use. Obviously that only works because mine in a place where it doesn't get in the way. As others have mentioned, sunshine and fresh air can also help, as can sleeping better and being less stressed. I imagine chalk use is probably horrific for it so maybe time to give up the white stuff...? On a more positive note, I've also had success controlling it through diet - cutting out dairy and wheat made a big difference - so you could consider trying that.
Interestingly, mine seems to be spontaneously clearing up after 16 years of being present but that's probably little comfort to you!