What Causes Recurring Cut Like Sore On Top Of Penis Shaft?

Hello. For the past couple months I have had an on again off again small cut like sore on the top of my penis shaft right below the head. It seems to be just dry skin but nothing I do seems to heal it. I have read as much as I can about men with similar issues and there is a wide range of things that seem could be the issue. Is this common and do you have any clue what it could be. One small cut no blisters or other discomfort. Thank you.