Thanks for the question. The moment you notice some abnormalities on your penis it is better to rule out the chances of STD. Since you are clear off it, your doctor will look for any sores like herpes as well as syphilis infection and also will be able to tell you whether you have got any warts. You don’t need to actually worry about these spots as they may be some anatomic variations that can happen to the penis which is quite normal depending on what actually they are. It is better that you take the advice from your general physician who can guide you after studying your skin and penis better. Medication is better when the same is prescribed after physically diagnosing a particular condition. But I feel there is nothing for you to be worried off with the white dots on penis.