Chronic ITB is most likely a running form, shoe, or hip muscle imbalance. As the previous poster said, you are probably pronating.
This may not help you, but it might help others with the same problem. Stand in your running shoes. Step forward with the foot on the side of your ITB pain. Put the forward foot down, but keep your weight on the rear foot. Now, shift your weight over the front foot. Does your ankle rock inwards? If so, that's pronation. You need to fix it.
What works best for me is a Superfeet Black insert. Go to a running store. Put them in your existing running shoes and try the foot forward drill described above. Does it eliminate most of the pronation? If so, that would be a good place to start.
I usually have to add a small square of cloth between the hard part of the Superfeet insole and the soft upper part. I'll put about a 2 inch square piece of felt there on the inside of the arch. Sometimes, I have to overlap 2-3 pieces, but eventually, my foot no longer rocks to the inside when I put weight on it.
That should resolve the pronation. That may or may not resolve the ITB issues.
Meanwhile if you want to try a DMSO-type liniment, I'd suggest Thermaflex (a horse liniment), an OTC arthritis liniment, or Volteren Gel (a prescription anti-inflammatory).
They will help with healing but they don't address the underlying issue.