My son always gets hayfever in the spring. This year I gave him butterbur and nettles. I also explained the role of milk in allergies and convinced him to just give up dairy for two weeks to see if it made any difference.
After a few days I called to see how the butterbur was working for him and he said his allergies hadn't been that bad and he hadn't had much chance to try the butterbur.
After a week I asked him again and he finally admitted that since he'd stopped drinking milk his allergies had completely stopped, but what finally convinced him to give up dairy for good was the side benefit that his skin was all cleared up. No more allergies AND no more zits. Not a bad deal!