Dark sumps on the scrotum are often angiomas, benign collections of blood vessels. These are common in middle-aged men. Your dermatologist can tell you for sure. I have only very rarely had to cauterize them to stop bleeding, but that's easy to do if needed. Protopic is a nice and effective nonsteroid for the groin. If it works, you should use it as needed.
Best.
Dr. Rockoff