Combination Therapy With 5-Fluorouracil and Photodynamic Therapy in Post-transplant Premalignant Skin Disease

Inclusion Criteria: * At least 18 years of age * At least four (4) actinic keratoses, located on face, ears, scalp, forearms and/or dorsal hands. - Patients in the solid organ transplant arm of the study must have had either a kidney or liver transplant, and the transplantation surgery must have occurred at least 2 years prior to enrollment. Exclusion Criteria: * Pregnant or nursing * Currently participating in another clinical trial * Using any topical treatment for their actinic keratoses * Currently being treated for other cancers with medical or radiation therapy * Patients with a known hypersensitivity to 5-aminolevulinic acid, 5-fluorouracil or any component of the study material * Patients with a history of a photosensitivity disease, including porphyria cutanea tarda