Assaalamualaykum WW
I pray you are in the best of health and happiness.

My sister in law has eczema and occasionally she has severe flare ups on her face. She is currently suffering from a flare up and her face is swollen and sore. When she performs ablution her face stings and she has to reapply steroid creams over the recommended usage, which is not good for her skin. The dermatologist has also recommended she avoids use of water on her face. In such circumstances would it be permissible for her to do tayyamum?

Jk khair