I Have A Red Raised Area On My Wrist. Its

I have a red raised area on my wrist. Its been there for 4-5 months. It looks like a burn. But won't go away. It started with itching in between my fingers and when the Dr couldn't tell me why I just went home and then was looking for something I could've been allergic to that's when I realized a shampoo that I was using on a customer, Denorex, was causing the itching. I started using gloves but it got o n my wrist and a red raised area came up. I have used cortisone cream and quit using the shampoo on my customer. It burns sometimes and I use aloe gel on it. Still there. The red is getting lighter but it looks almost a purple color underneath. Its not scaley or a scab.