Kids and she was using baby wipes. It was first diagnosed as eczema and treated with steroid creams. But that never really helped.
She saw an allergist and did an allergy panel and had quite a few contact allergies to different preservatives in soaps, detergents, shampoos, etc. the biggest one was an allergy to sodium benzoate, which is in most soaps and detergents.
It’s a pain, and she still gets flare ups if we aren’t at home with our stuff, but it’s much more controlled.
Have her see an allergist and get a panel done on her back with all the different preservatives. I would bet she is experiencing the same thing.