Allergic reaction to what?

Anonymous
i had an allergic reaction today it was on my right thigh, I was at the park just sat in the grass then pushed my cousin on the swing and left and as I left my leg starts to itch so I itch it and it won't stop itching and it begins to burn I go back to the house to find my thigh red and bumpy and the area that's red and bumpy feels hot it was a burning feeling, I washed my legs off in the shower and went to look at my pants after the redness and bumps went down and there is a white ish thing where my allergic reaction on my thigh was and it looks almost like a powder how did that get on the inside of my pants and what could it be? and how can I prevent this any and all help would be appreciated.
Allergic reaction to what?
4 Opinion