Why does only my left buttock itch?

Fascinating question. Commonly, when something itches, it must be scratched. However, picking at your buttocks is an unsightly thing, even here in the backwoods of texas. It is hard to see your face through this monitor, and your rear is even harder to visualize. Probably the best thing you could do would be to show your derriere to a doctor. Maybe you have a rash you cannot see?