Thanks for the query,
Yes your dryness of skin as well other symptoms can be due to warfarin
In fact any drug can cause an adverse reaction and the presentation varies in different people.
As warfarin cannot be stopped try to use some shampoo like sebowash.
She might get relief with this.
Please meet a dermatologist
for final diagnosis and treatment
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.