You haven't said where it is , it can be multiple places and it certainly isn't confined to men. How I have treated it is to get some powdered boric acid and make up a solution of 1/4 teaspoon to 1 cup boiled water. Place in a jar that you have cleaned and rinsed with boiled water, have a lid that you can place on it to keep fresh. Rinse the area with this at least twice a day. (Place a small amount in a cup so you don't contaminate the whole amount.) Pat dry with a clean towel and then cover with diaper rash ointment. (Usually zinc oxide.) You may also put a medicated powder (Such as Gold Bond over this.) If this doesn't help in a few days, see a doctor. This was an approach that I learnd from a doctor years ago. Boric acid made up like this also makes a good eye wash, but it is poisonous to drink so label it and put in a safe place out of little one's reach.