Is there a nerve under the area of the pinky toe that would cause pain all the time?

Yes: Every toe has 4 nerves in it. @ on the top (dorsum) 2 2 on the bottom (plantar). The nerves on the botom can become enlarged and painful as in a morton's neuroma , though rare in the 5th toe. Trauma , surgery and poor shoe fit can also cause nerves to become painful.

Nerves innervate: All areas of skin. The nerve itself can bother you and it can be problematic in a different location. Having said that, it is not a common spot to have nerve pain, though certainly possible. I would see a podiatrist for an in person exam.