Thanks for your query.You have a etching over scrotum
and head of the penis .Are you diabetic ,If you ahve not tested your blood Sugar levels so far then get it done to rule out Diabetes
.From the description it looks like a fungal infection
Clean the entire area with soap water twice daily and apply Tropical anti fungal Gel like Mecanozole.
Wash your inner ware in hot water mixed with antiseptic lotion like Dettol
Depending on the blood sugar report (if turns to be positive) consult some Physician for proper management of Diabetes.