Natural health: Lichen - a chronic skin disorder

I have a friend, in her early 60s, who has been living in France for more than 10 years. For the past year she has been suffering from a condition called Lichen and is at her wits’ end. 

The ‘rash’ is all over her body, legs, and arms and is excruciatingly itchy. Thankfully her face, head, and mouth are clear.

Her doctor prescribed cortisone and various creams. It helped for a while but did not completely clear it. But it came back strongly again but she no longer wishes to go back on cortisone and was hoping to treat the condition naturally.