'I am about to start using fluorouracil 5% cream on my hands. I need to know how often I can wash my hands and can I use soap or plain water.' I have squamous cell carcinoma on the backs of my hands. I had three lesions removed surgically 10 days ago but I have many more surrounding them. They are not totally healed. Since I need to put the cream on my hands I am concerned about it getting into my eyes or other areas where it could cause problems.