Grapeseed oil symptoms and conditions

Ive been on warfarin for 18 years at 15 mg ,INR 3.2 and in the last 3 years I have doveloped a really itchy rash(below knee) that just wont go away.It often becomes infected and has to be treated with antibiotics.The infection goes away but the rash keeps on itchin! I found teatree oil and grapeseed oil mixed together ease it but i need a cure before I chew it off at the knee.Sometimes I scratch in my sleep ,and the result is a venous ulcer.(the last one took 18 months 2 weeks and 3 days to heal).Any ideas?