I was crashing about in the undergrowth last Thursday, picking up dead fatsia leaves that had fallen on to things, and as I emerged from the border, I felt a strange burning sensation on my left leg. It wasn't agonising, just a vague burning, as if someone had applied a cream that had irritated my skin. I didn't really think anything of it, but by the time I'd been in the office all day, my lower leg and ankle had swelled so much, I could hardly walk. There was absolutely no itching at all, just pain, which was mainly caused by the swelling. I often react badly to mosquito bites, so when I got home, I took some antihistamine. After a night's sleep, and two antihistamines, the swelling had gone down a bit, but my leg still looked very red, so I went to the doc. (I had a bad bite last year, which got infected, and my whole arm swelled up, so I'm a bit twitchy about these things.)
The doc said it didn't look like an insect bite to him, and I agreed that I hadn't felt a sting, such as you might get from a wasp, and that I had felt the burning, which I wouldn't have got from a mosquito. He said it looked much more like an allergic reaction to some sort of plant, and his guess would be euphorbia, which leaves a distinctive red weal. We marked off the red area in pen, and he told me that if it spread beyond the marks, to take the antibiotics he gave me, and to try to keep my leg up to reduce the swelling.
There was some euphorbia where I'd been crashing around (E. amygdaloides 'Purpurea' to be precise) which I had cut back a couple of weeks earlier. Sensibly, I'd used rubber gloves when I cut it back, but stupidly, I'd forgotten it was there. I'm fairly sure that's what it was, as the euphorbia is the only plant in that area I can think of that is known to be a skin irritant.
By the time of this post, the swelling and the inflamed patch has gone down considerably, thanks to five days of antihistamines. You can just see the pen marks that showed how far the inflammation extended, but there's still a very obvious dark red mark on my leg which is where, I suspect, it rubbed against the euphorbia stems. I've posted the picture below as a warning to anyone like me who doesn't take the 'Toxic!' warnings on plant labels terribly seriously.
