What Do Rashes And Severe Pain Indicate Despite Taking Cortisone Cream And Benadryl

Question : I contracted a rash over the weekend. It looked like contact dermatitis or hives at first. That night I took a benadryl and went to bed. when I woke up, it had spread down the backs of my legs, turned red and burned. I made it to the shower where I collapsed. When I made it back to bed it had spread to the front of my legs and I was in severe pain. I had to really concentrate to make my legs move. My wife brought me cortisone cream and benadryl. The rash continued to spread and covered my entire body. The pain was nearly unbearable. I found it difficult to stand and to concentrate. My wife reports that my speech was slurred and thoughts disconnected. Over two days, I improved. Now my feet are still swollen (right greater than left). If I take many steps my left leg becomes sore and then goes numb. My thoughts still seem slowed or "blurry". I have no idea what happened to me. I could not find any pictures that remotely resemble what I had. It was like watching a slime mold move under my skin followed by multi shaped eruptions that turned red and burned. Any thoughts?