A friend gave me some rhubarb from his garden, and I began to cut it, but then started itching bad all over my body and had breakouts. Strange thing is though, I can eat rhubarb cooked, so I'm not allergic to it.
Its a common allergic reaction to touching rhubarb. I am not sure why you are not allergic to the cooked plant but your syptoms are classic for an allergic reaction. Have you ever touched raw rhubarb before?
I've read that the leaves are toxic...years ago when my kids were tots there was rhubarb growing behind the garage..we had to fence it off to keep them out.
I had never touched rhubarb before until that experience, but had eaten it cooked prior to that.
Rhubarb & other greens such as Taro leaves contain a large amount of oxalic acid which is store in the cells as Calcium oxalate crystals. Its these crystals which literally embed themselves on the nerve endings giving rise to the itch or irritation when the cell membrane of the rhubarb is punctured upon cutting it. The crystals dissolve in acid which translates to cooking the produce in an acidified water to leach the oxalate out of the cells.
The oxalic acid is in the leaves, not the stalks, so you shouldn't have a problem eating the stalks. If you have a reaction a serious reaction, treat it as a poisoning. Call poison control at 800-222-2222: http://www.nlm.nih.gov/medlineplus/ency/article/002479.htm.