How To Manage Pain From Rashes On Body While Treating Lung Cancer?

husband is on morphine since 11/2014 for lung cancer that metastasized to bone. Given 2 mo to live..chemo nor radiation had worked. We keep increasing the morphine but pain is still excruciating...doesn t seem to help. His feet and hands have swelled with a horrible rash. Been that way for 5 wks now...no one seems to know what this is from. Could he be allergic to morphine? Could he have built of a tolerance to morphine so its not working? what else could he take for pain if can not take morphine?