Hi there!
This is likely to be due to frictional trauma and associated inflammation; which is likely to get better on its own in a few days. You could try keeping the region adequately moisturised and avoiding trauma. If the symptoms fail to resolve in about a week, you may consider an evaluation by a primary care physician to looks for secondary causes such as infections, inflammations, growths/ masses etc and for appropriate management.
Hope this is helpful.
Take care!