Hello. I Seem To Have Developed What Started As A

hello. I seem to have developed what started as a single red blotch slightly noticeable on tip of penis that slightly crusted with time. It is in one spot and.doesnt seem to.go.away.
Now a smaller redder blotch appeared above the original one. I have had unprotected oral sex a few times about the time they appeared but they also have appeared after taking viagra pills. I would believe it.to have more to do with the unprotected oral sex though.
What can it be? I am hoping it.isnt syphilis...