Nerve Damage in tip of Penis?

I recently visited a dermatologist to get checked for STDs because I had been feeling a tingling sensation only on the tip of my penis every 2-3 weeks which would last for 2-3 days.  The dermatologist couldn't find anything out of the ordinary, but suggested it could be nerve damage.  He wants me to see him again if it doesn't stop by the Summer.  Is something like this common?  He "ruled out" HSV and HPV because of the frequency I've been experiencing this feeling.  Just curious as to what your thoughts are about it being nerve damage.  This has been going on since 12/15/04 when I had an encounter with a paid escort and have been agonizing over it ever since.  Thanks.

[CCF-Neuro-M.D.-PW]

Nerve damage isolated to the sensory nerves supplying the tip of the penis would be highly unusual

If a sensory nerve disturbance was present, other areas such as the feet/ankles would be affected also, (and usually first)

IF there was significant trauma to the tip, ie crush or laceration, a neuroma could develop over time (a bundle of overgrown nerve fibers)

However, a process in the skin (epidermis) or just under the skin (dermis) may be more likely to be the cause rather than a primary neurological disorder

[Csaw]

In addition to the "tingling" sensation I've been experiencing, I've also felt this uncomfortable, "weird" feeling in my armpits.  They don't hurt at all and are not swollen, they just have this feeling I described.  Is this nerve related?  I have been stressing over my health for the past 4 months and am curious as to the correlation of the nervous system to these "symptoms" I've been experiencing.  Thank you for your time.