What Causes Rash In Armpit Radiating Down The Arm And Hip?

2weeks ago l got a rash under my armpit than down my arm than the side off my body than the hip area around the back to the balls and the back of my legs just in the joint area , around the hip area the skin had lumps every way to big to small, in the morning gone now just last night it happen again but with more swollen than gone in the morning you view?