Why are there red rashes on my glans penis?

Hello doctor,

I had unprotected sex three months ago. I had all the tests except herpes done and all were negative. About every one to two weeks since the encounter, I have been getting red rashes and red small dots all over my glans penis and foreskin. They are not raised, they do not itch. They are maybe like two seconds a day and no discharge. Although sometimes penis can produce an odor. The dots will disappear on its own usually after three days and can reoccur again after a week or two. There is nothing that seems to be indicative of herpes. Penis also seems very dry and wrinkly at times. All STDs (Sexually Transmitted Disease) and HIV tests were all negative.