Welcome to JustAnswer Health...and thank you for your question. I am a verified Expert and am delighted to help you today.Does it look like this?
the tip of the penis occasionally gets red but then it disappears, but recently a boil has now appeared on the outer skin and on the out side of my testicles.
Per Emedicine.com this is the recommended treatment which is pretty much standard, but before you are sure this is what you have, FIRST go to your Doctor so he can examine and diagnose you:
Treatment with medication is effective in shortening the initial outbreak of the infection, lowers the chance that the infection will come back, and makes any later outbreaks less severe.