How to stop pain on the little toe joint outside of the foot and under the little toe?

How to stop pain on the little toe joint outside of the foot and under the little toe? This starting after walking in slightly narrower shoes eventhough I had no pain while walking, it has been a week and the pain remains the same. Xray and MRI do not show anything like stress fracture or tendonitis. Pain only happens when putting pressure on the side of the foot and walking, not when resting.