I don't react to poison ivy unless I break the stems and get the sap on my skin, and I'm usually pretty careful to keep an eye out for the leaves and stems, so I was surprised when two of my fingers started to break out in itchy blisters a few days ago--the only gardening I had done recently was pull weeds and mow grass. After a raised rash started on the back of my neck, I knew it wasn't poison ivy, so I looked up goose grass (aka cleavers, velcro plant, sticky willy)--the weeds I'd been pulling. I've pulled them by the handfuls before, never had a problem that I recall, but I found out that exposure to sunlight after contact can cause the blisters and rash.

I had mowed grass for a couple of hours after pulling the weeds (without sunscreen--my bad), and the rash is mostly on the back of my neck, and the side of my neck that was exposed to the sun--the side my thick braid covered isn't blistered. I must have wiped sweat or brushed a bug off my neck, while I still had the 'juice' on my hands.

There's no pain, and the blisters on my hands and arms look like contact dermatitis from poison ivy--just here and there. I have nothing on my shoulders, torso or legs (I was wearing jeans and boots), and the blisters have broken out over the course of several days. Other than the infernal itchiness, which is starting to abate, it's not causing any problems, but I had no idea this could happen--I'm adding galium aperine to my spray list, with poison ivy. I grow galium odorata, sweet woodruff, with no problems, and it evidently doesn't cause the same reaction.

Have you ever had this reaction? This is a pic of the invasive weed, which I've read is sometimes used as a herbal remedy for certain skin conditions, and can be eaten in salads when picked early in the year:

wiki--contact dermatitis/photoxic dermatitis

So be careful out there!