Since it is considered to be an auto-immune condition (the body attacking itself), my theory is that, as with all auto-immune conditions, a decrease in intake of foods known to cause sensitivities, esp. gluten (wheat, oat, barley, rye), would help, as would increasing the intake of fruits (e.g. berries) and green leafy vegetables and cruciferous vegetables (e.g. broccoli) which contain the highly beneficial phytonutrients like carotenoids, flavonoids, polyphenols, indoles, lignans and isoflavones.
Whatever you do, do not be talked into taking steroids or, heaven forbid, immunosuppressants. Things may seem to improve in the short-term, but you're just asking for trouble long-term. Good luck!