Thank you for the responses everyone!
Try a natural soap, like Sappo Hill. I use the one called Natural. I have very sensitive skin myself.
I apologize that my above post wasn't very useful.
I have problems with skin care products, in particular shampoos, soaps, deoderants and shaving creams. The chemicals I have most problems with are propylene glycol and sodium lauryl/laureth sulfate. I also have issues with aluminum in deoderants/anitperspirants. I found this out using the technique I'll describe below.
As allymarbles mentioned, there are two types of soaps. I have issues with detergent soaps. The soaps I make are plant-based, oil soaps, in which the glycerin is retained. That's why I have no issues with the soaps I make. My guess is that your gf also has problems with the detergent soaps, so that's where I'd start looking. I'd first consider the soaps with which she's had problems already and go to the store or whatever and look for commonalities in the ingredients. Her problems could be due to the chemicals, fragrances or both. The chemicals would be the same from soap to soap, but the fragrances might be different...just note whether or not the soaps have a lot of fragrance. Once you notice common ingredients, your gf should try soaps without and without those things and see how her skin reacts. I think she'll be able to find the culprits using this type of method. It's a bit tedious, but it does work.
She can get some steroid cream if the rashes last for a while (it makes them go away faster) and if she gets itchy, something like Xyzal, Zyrtec or Benadryl works well. The steroid cream and Xyzal are by prescripion...Zyrtec and Benadryl are OTC
If she finds she's having a problem with most of the commerical soaps, making her own plant-based, oil soap might be a good option. If she wants more info about that, leave a note on my page and I'll be happy to tell her more.
Lots of luck!!
The first thing to determine is whether she is affected by detergent-type soaps, or the more old-fashioned oil-type soaps. The former are acid and made with a variety of chemicals.. The latter are alkaline.
I make my own soap...no more irritation.