I'm about to turn 50 and for the last couple of decades I have experieinced in tense itching from a tiny, "pinhole" area on my scrotum. The origin of the itch seems to be just below the skin surface and there is no bump or anything (until after itching there is a a tiny rash area). I don't have a clue what brings on these isolated/one evening episodes of insatiable itching, but I can often go months without experiencing any. Actually this itchy spot seems to act up much more often of late, which is why I'm writing this. Actually it seems that lately my entire srotum has been rather itchy, but nothing like the one tiny spot ont he right side.
It could be a fungal infection, eczema, or some kind of skin irritation. Have you tried over-the-counter antifungal creams? What have the doctors said when they examined you?