A 73-year-old Caucasian man presented for ĞǀĂůƵĂƟŽn of a one-month history of painful, ƉrƵrŝƟc rash across his lower abdomen and lower back (Figures 1 and 2). Two years earlier, he was diagnosed with stage IV invasive colorectal adenocarcinoma with mƵůƟƉůĞ ŚĞƉĂƟcÍ• pulmonary, peritoneal and osseous metastases. He had previously undergone surgical excision of the primary mass in his colon, chemotherapy with mƵůƟƉůĞ drug regimens and radiotherapy to his right hip. At the ÆŸmÄž of ƉrĞƐĞnƚĂƟŽn in our clinic, the ƉĂƟĞnÆš had been treated with Lonsurf® , a cŽmbŝnĂƟŽn of ÆšrŝŇƵrŝĚŝnÄž (a thymidine based nucleoside analogue) and ƟƉŝrÄ‚cŝů (a thymidine phosphorylase inhibitor), for one-month ĚƵrĂƟŽn