I got tested or STDS over a week ago and i'm still waiting for the results. My question is what would cause a greyish patch with a dark ring that is located on the underside of the penis head stretching from the urethra down a bit? It has been itchy and caused slight pain a couple times. There seems to be thinned out patches of skin that appear then disappear in different spots of the penis head. I seem to have yeast type symptoms of the head at times. I'm tired of waiting/worrying and any insight would be great.