Thank you very much for your opinion, doctor. It is good to know about the possible causes of the rashes. I will follow your advise and see a dermatologist. Thank you for your help.
Welcome to the forum. I'll try to help.
Penile bumps of the sort you describe are not typical for any STD. The only possible STD that conceivably could explain such a symptom (e.g., genital warts, molluscum contagiosum) cannot show up sooner than 2-3 months after exposure, so even if it's one of those problems, you didn't catch it during the sexual encounter a week earlier. And that encounter sounds entirely safe; you can't catch an STD through an intact condom.
As for other causes of your symptoms, I can't go into detail; we don't speculate about non-STD explanations for genital symptoms. I'll just say that no STD causes red bumps that fade, or that vary in prominence in the way you describe; most genital rashes are not due to STD; and most of the many conditions that cause skin rash anywhere on the body can sometimes affect the genitals. To your specific questions:
1,2) I agree with your self-assessment of the low risk of the sexual encounter you have described. If this is your only potential STD risk, and on the basis of your symptoms, I don't recommend any STD check-up or testing.
3) See above; this doesn't sound like either herpes or HPV.
4) Profession examination is exactly what I recommend. A dermatologist would be ideal. An STD clinic would also be OK; as you might imagine, STD clinics generally are very experienced with all kinds of genital area skin problems. However, I don't recommend any particular test; just follow your doctor's or clinic's advice once you have been examined.
I hope this helps. Best wishes-- HHH, MD