I am sure the medical books explain what the problem is with this. I would suggest anything with the skin has something to do with an iron problem and what ever the skin looks like, I have read that is what the outside of the organs look like.
What ever the reasons, only your red blood cells can cure the problem and the orange juice fasting is the premium method.
I am sure you would have to do everything correct for at least a year and odds are this would be the last thing to correct its self. You have to treat the body as a whole always, to chase this problem away from the skin would only cause more internal problems, many times as things come up and out the skin it is a method of saving your life, When you attempt to heal it naturally it may get a hole lot worse looking as it comes up and out. The sitz bath and oregano oil would be 2 great methods along with plenty of potassium/iron from plant sources.