How To Get Relief From Pain Due To Herpes?

My mom (60 years ) was diagnosed with multiple myeloma in nov. 2010 and finished with chemo treatment last month . Few days after the completion of her last cycle of chemo treatment she developed harpies. My Query is :
Does Harpies involves a a life risk ??
How can the pain involved in it be reduced ??
Is it a result of chemotherapy ??

Please suggest.