Hypoallergenic briefs, pullups or booster pads?

When Mom became fully incontinent of stool and urine, her bottom looked burned. We have used Nystatin powder and cream, and numerous good name brand barrier creams and ointments. Now some areas of her skin are leathery and peeling (the healing parts) and other areas are so thin that they ooze and need to be covered with wound dressings.

My sister suggested maybe Mom is allergic to what the pullups are made of (we use Depends). I've tried very hard to keep her dry, but her skin has been in this condition for over a month.

We've tried exposing the areas to air (2-3 times a day at first, now down to once a day because it doesn't seem to be helping a whole lot). It helps for a little while (hours) and then either her thin skin oozes, or she scratches and bleeds, or she is wet and is raw.

I'm also at a loss about what to do at night. I still work full time (and am no spring chick so I need my rest too) so getting during the night isn't realistically feasible. I've thought about having her sleep with just PJ bottoms on, but I don't think that would better than an absorbent pullup or brief. I use Medline Extrasorb pads under her, which seem to do the best to wick the wetness away, but it's still wet.

I've thought about using large booster pads (the kind you can put in a diaper) in her slacks during the day and PJ bottoms at night if I can get her to try them. It would make it easier to know when she is incontinent and she can sit on a waterproof pad so she doesn't soak her chair. It might cause a problem if she is incontinent while walking (which she often is because by the time she knows she needs to go, she has gone before she gets to the bathroom).

I'm thinking out loud, I guess. Anyway, if anyone has suggestions, I'd appreciate hearing them.