Check you're not exposing yourself to the same sort of toxins on a daily basis. Have you started doing something more frequently recently than before?

It's difficult to help without seeing pictures - I can't even look stuff up for you, though I'm sure you've done a lot of that yourself. However, I understand it's in a private area. I'm curious - have you considered the reason the fusidic acid was effective? I understand sometimes the problem is fu...

UPDATE: The dermatologist confirmed it's definitely not scabies, as it didn't respond to the treatments. He said the reason I stopped itching for a week or two after the treatments was because those creams are doing more in your skin than just being insecticides. However, he has no explanation of th...

Oh, dear - that does sound very difficult to live with and to manage. You have my sympathies.

What happens if you leave it alone for a week, not washing it at all?

Can anyone please identify this condition? I've treated with permethrin four times to no avail - and I've been extremely thorough with all the environmental procedures for sterilisation. The condition is briefly deleted by the application of permethrin to my entire body, including head and face. But...

I've found soap is the primary cause of dryness. Try a weak - and further dilute it with water - shower gel instead. If you're extremely sensitive, try one without perfume.