Allergic reaction to Hop vines

[TLCox]

My wife planted two hops plants for accent plants.
She was working with them yesterday, and broke out with severe rashes on both of her arms.
Does anyone know what chemicals are exuded by these plants?
I had a few scratches from helping her, but nothing like what she suffered.
She put Aloe lotion on them, and they look better today, but there are still quite a few welts.
They are similar to welts that she got from handling Rue plants a few years ago.
Thanks
Ted Cox

 

[Hang Glider]

Hop is cultivated for its use in beer-making. It is also used as an ornamental vine in many areas. Hop pickers can develop dermatitis from working with common hop plants (Raith and Jager 1984, Fuller and McClintock 1986). In addition to allergic responses, the hairs on the leaves may cause mechanical abrasion of the skin (Fuller and McClintock 1986). General symptoms of poisoning: 1- Humans: a- blistering; b- conjunctivitis; and c- erythema. (references)

Hops: hardy perennial vines of Europe, North America and central and eastern Asia producing a latex sap; in some classifications included in the family Urticaceae. Source: Wordnet 3.0 Copyright © 2006 by Princeton University. All rights reserved.

from Webster's Online Dictionary on Humulus Lupulus

 

[cram]

I think this is fairly common. As you've noticed, the bines have a rough texture so they can climb, which can irritate the skin, too, kind of a sandpaper effect. I always wear long sleeves when harvesting hops (or working around them)...otherwise, I'll look like I was whipped. Wearing sleeves and gloves would likely offer enough protection.