Allergic disease is definitely a pretty complex topic still, as most aspects are still nebulous to us.
Can they go away forever, though? That appears to be the case, as cloud said:
Quote (cloudkicker @ Oct 2 2014 05:06pm)
not cured per say but theres some evidence for desensitizing the immune system to the allergen, the magnitude of desensitization varies and isnt great though
some allergies developed in childhood also can be outgrown, but not always
Many allergies are outgrown.. for instance eczema is almost always outgrown and asthma has a high rate.
Some studies have suggested it's not an actual "cure" as he states ^ it really is just a mechanism of desensitization whereby your body becomes tolerant to it. Seems to happen via a persistant, ongoing, low-grade exposure to the allergen versus an intermittent robust exposure that many come in contact.
For instance, they've tested the desensitization method on peanut allergies and found the low grade chronic exposure greatly ameliorated responsiveness. The only caveat is that it does vary between individuals quite a lot and we simply don't know how long that effect will last.
They do use the desensitization method clinically where they repeatedly administer small quantities of the allergen subcutaneously. Specific IgE levels decrease and IgG titers typically rise, further inhibiting IgE prod by neutralizing the antigen and via antibody feedback (ITIM signaling), and it may induce some T-cell tolerance by changing the predominant phenotype from Th2 to Th1.