What Causes Redness And Itching Sensation On Left Shoulder And Breast?

Hello, I have a red area covering my Lt shoulder and going across to half of my breast and down my lt. side. It is very red and itches. It feels hot to the touch and maybe a bit swollen. I have been out in the woods in Wa state picking berries. The red area is very painful, itches and burns. If I push on it several places are very painful. Any ideas? Sorry I didn t know I had to pay. Sorry I wasted your time.