my mums had it for ages and has even been to hospital for some light treatment which seemed to work but was very time consuming (3 times a week at an hour a time)
my brothers got it bad as well, but he's been ok ever since he's had some chinese herbal cream he uses on the worst parts every day
my sons got a touch of it as well and they've given him som ecream which i'll find out the name of when i get home, but that was great at clearing his up when it flared
a word of warning, there are some chinese herbal remidies that you drink which clear it up double quick time, but the side effects are that they taste like shit and the small matter of them fucking your kidneys up because there are so many other things in them stopped my brother from taking them