Don't know how to get my wife to stop doing dishes

Some background to this: my wife recently gave birth and around the same time started getting dermatitis around her fingers.

I work nights and study days but remind her daily to just leave the dishes alone when i get home. I don't have an issue with her doing other things and I understand that she wants to help out still and not 'melt into the couch and become a potato' (her words). What worries me is every time she touches the dishwashing detergent her dermatitis will flare up again. I've tried asking her to help around in other ways (folding laundry, packing the dishes instead) while I deal with the cleaning, dishes, laundry and cooking.

But she keeps washing the dishes!

I understand she's only looking out for me as I apparently look like I'm going to drop dead from lack of sleep but in my defence, my eyebags at this point aren't going to all of a sudden disappear.

Does anyone have any tips? Am I missing something? I feel like I'm overlooking something but don't know what and everytime I ask my wife she just says 'cause you looked tired'.