I Have Suddenly Got A Skin Rash On My Torso

I have suddenly got a skin rash on my torso and top of arms and it is now around the base of my neck. rash on my lower torso is separate quite large red spots (not raised). Slightly larger on top of arms and quite an intense joined up rash to base of neck. I have recently had a scalp problem, very itchy and severe dandruff and have used Nizoral about 3 times so far. Not sure if the scalp problem is connected.