If external influences are excluded, your condition may be caused by folliculitis or blood clots.
Suggestion:
You can try: local temporary cold compress, cold compress with a towel for another ten minutes, and do a gentle massage before going to bed at night!
It will have a good effect.
If it doesn't get better within a week, it is recommended to go to a big pharmacy to see a doctor or have a check-up.
I hope I can help you and get your approval.
Here's to health!