In the past 6 or so months, every so often I have a red rash appear on the head of my penis. I have made a link that the rash only really occurs when there is semen present under the foreskin of my uncircumsized penis (eg. from post-cum after masturbation). I practise good hygiene so it's not like i leave this festering for hours and hours, the rash can appear as little as a couple of hours after the semen being present within the foreskin. The rash has varies in intensity and has heightened sensitivity to the unaffected areas, and also contains small raised red bumps. It usually goes within 3-4 days.
Not sure if this is linked but I have previously been diagnosed with and treated for chlamydia (over 6 months ago), and have been cleared of STDs using urine and blood samples very recently. Unrelated to when the rash is present, I have almost a permanent tingling sensation in my urethra, and every now and then, slight pain in the testicles.
Any thoughts on this would be much appreciated.