I second sosick. If this is fungal/parasitic in nature or has its roots there, she'd be wise to address those problems, as the skin is just a reflection of the turmoil inside.

So often it's fungal/parasitic too. She would be wise to oust all sugar and wheat/gluten and yeast and possibly milk from her diet also. Those things play havoc and feed fungus, candida and parasites.

And consume more healthy foods at the sametime. I don't know if there is any "cure", apart from helping the body do the job itself...which in the end is the only cure anyway.