Trail/off-road running leg rash. Plant rash. (horrible photo warning)

ChampionRabbit

The paths I regularly run on are pretty overgrown this time of year, and I get a rash that covers the fronts of my legs. The entire part that isn't covered with sock/shoe and short is covered with rash by the time I get back.
It can't be all nettle; does anybody know (just out of interest) what the most likely cause is?
It usually goes by the evening (assuming early morning run).
Please excuse my horrible knee!

ChampionRabbit

Ok, so image posting doesn't seem to work!

Bad Teacher

Hi I get this as well every summer the bottoms of my legs are red swollen and itchy.  I assumed due to my hay fever it was the grass I use a bit of Sudo cream it's worth it for the Off road running. 

thisgirlruns

Hi, I get this rash too. I put it down to grass pollen

ChampionRabbit

I get hey fever too so you're probably  right. Hadn't occured that it could be grass!

Bad Teacher

Sudocream and piriton are your friend if I go really off the beaten track I get it on my arms as well not attractive this running lark