Irritation On The Shaft Of Penis. Skin Turned Sore, Whitened And Small Brown Spots After Application Of Cream. Reason?

Hello, I have an irritation on the shaft of my penis that is worrying me. About 3 weeks ago I had a raised red patch of skin on the shaft of my penis. Fearing that it was herpes I went to the doctor and was told that it didn t appear to be herpes but rather some dermatitis . Regardless, a culture was taken and grown out and came back negative for HSV 1 and 2. I was given Nystatin and Triamcinolone cream and told to apply twice a day. I did this and the area was clearing up so I stopped using the cream and a day or so later I got a swelling in the same area of the penis which turned into a sore with whitened skin. Now there are tiny brown spots on the underside of my penis. Could those spots be from the cream? What does this sound like to you? I exercise everyday and always sweat a lot, and I feel like all of this may have something to do with that. Thanks for any help