What Causes Rashes That Starts From Back To Arms Having Diagnosed With Lymphocytic Leukemia?

Hello my mother is 65 years old and would be considered in poor medical health. She was diagnosed with CLL (chronic lymphocytic leukemia) two years ago and has also had trouble with blockages in her upper arteries. She had a successful surgery to clear one of the blocked arteries and her cardiologist assures us the rest of the blockages are NOT life threatening and are not getting any worse at all. The concern is she now has a rash that originated on the back of her head and moved down her arms (the blockages were in her subclavian arteries). It has been 3 months and she just told me now. I have a BA in biology and the symptoms don t seem to fit either of her major problems. If it were arterial, I would expect necrosis of the finger dermis, not a rash. The CLL apparently may cause rashes but she has no swollen lymph nodes in either her neck or arms. I have a picture to accompany that shows the rash. I m sorry to trouble you but I am deathly afraid and don t know what I would do without her. She is also quite scared to go into the doctors and hear that she has weeks left to live (I considered stress as a cause for the rash)? She also had shingles 4 years back, but does not describe this rash as as painful as the shingles virus. Please help, I would be forever in your debt.