What Causes Sensitive Skin On Upper Thighs?

hi, i have developed in the last 7 days highly sensitive skin on my upper thigh, from above knee to the hip,especially on the outside. this is accompanied by heavy deep muscle pain and some red bumbp on the skin which are itchy. i thought it was because of laptop heat, because i had used it in my lap for a while and the location of the sensitive skin on my left upper leg was the same as where the heat from the laptom emanates. i am in serious pain, what can i do?