In article ,
Dave wrote:

I was gardening in a T-shirt, wearing gardening gloves, and a weed
cutting fell on my wrist. There was no immediate reaction but the
next morning it got very itchy and came up in blisters, and took over
a week to go away.

I've heard about poison ivy, but I thought that was an American plant.
What are the plants in the UK I should be wary of, besides nettles?
It didn't look like giant hogweed, and was quite small.

In a seed catalog of unusual plants I read a disclaimer to the effect
that for any plant, there's someone, somewhere who is allergic to
it, and for any person, there's a plant somewhere that will give them
the kind of reaction you describe. Possibly you've met your match!

Were you using any agricultural chemicals? People sometimes get dermatitis
from the components other than pesticides in these products.

You could also have been bitten or stung by an insect or spider. It's
not uncommon for the reaction to take hours to develop, especially if
it's an extreme reaction like the one you had.

You might consider wearing long sleeves, especially if it happens again.
If you figure out what caused it, post here and let us know.

(Hm, now that I think of it, Primula malacoides causes this kind of skin
reaction in many people, and you Brits are into primroses, right?)