Martha
I had a similar rash, started small and spread to my entire stomach. I finally went to an allergist. THe outcome: deathly allergic to eggs, onions and milk. Quit eating all 3 and voila, the rash is gone. On the cheap side, try evaluating your mothers' eating and what might make the rash worse or what she isn't eating when the rash gets better. On the more expensive side, go to an allergist for food allergy testing. I've got to tell you, it's hard to cutout eggs and onions. Almost every baked good has eggs, almost every prepared food has onions. I'll bet my cholesterol is great though. Good luck.