It must be too late to take out the stitches, and you didn't take out the stitches until the wound healed, which caused the suture hole to fail to heal and formed a small hole. As time goes on, some dust is stored in the small hole.

There is a way to cure it. Pass the tail end of the sewing needle through the small hole, and then cut it with a knife. Sterilize with iodine.

If you are afraid of pain, go to the hospital for plastic surgery.