I keep getting spots on my bum / groin area.What can I do?

Hi all,

So ideally I don’t want to go to the doctors unless I really need but like the title says I get spots on my bum and groin area but when they’re gone they leave horrible scarring and purple marks. Has anyone else had this?

Or know a way of preventing them. I clean the areas as much as I can with no purfume products but can’t seem to keep them at bay, I’m going on holiday soon and so self conscious about swimming. I’ve added a pic so you know exactly what I mean xx