Red Rash and white bumps/pimples on penis shaft, but no pain or itchiness. What is this?

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Not sure if you can see the file, but basically I have a red bumpy rash with white pimple on my penis. It is not on my entire penis should part of my shaft. I had an STD check a) bout 5 months ago and was clean and hav had the same sexual partner since 9 months ago so I assumed if I caught anything from her I would have got it by now. This rash started showing up around the time I got the STD test maybe a little before and the only thing I tested "indeterminate" for was mouth herpes. Basically I dont know what this red rash is or why there are white heads on my penis shaft so I was hoping for some advice on what it is and how to make it go away. Any information you could offer would be of huge help as I am extremely anxious about this situation.

Any thoughts on this?