Photodynamic Therapy-Induced Immune Modulation: Part III

Inclusion Criteria for Control Subjects: * Adult age 45 or older * Caucasian (Fair skin, Fitzpatrick types I and II) * Ability to understand and consent to the instructions of the study * Have access to stable transportation Inclusion Criteria for Study Subjects: * Wright State University dermatologist has prescribed PDT for the treatment of actinic damage (Presence of precancerous actinic keratoses whose treatment necessitates PDT with the BLU-U). * Undergoing PDT on greater than 5% body surface area: face and scalp, face and dorsal surface of arms, face and chest, face and back, or dorsal surface of arms alone, chest alone, or back alone. * Caucasian (Fair skin, Fitzpatrick types I and II) * Adult-age 45 or older * Ability to understand the informed consent and comply with instructions and have stable transportation. Exclusion Criteria for All Subjects: * PDT on less than 5% body surface area (eg, forehead) * Present treatment with corticosteroids or Non-steroidal inflammatory drugs (e.g., cyclooxygenase inhibitors) within past 2 months (except low-dose 81 mg aspirin). * On antioxidant supplements (e.g., vitamin C) for past 2 months * Tanning bed use within last 3 months * PDT treatments within last 3 months * Significant health issues that could affect the immune system (e.g., uncontrolled Diabetes Mellitus, Rheumatoid arthritis, skin rashes, psoriasis) that could interfere with testing * Pregnant or nursing * No immunosuppression, and on no immunosuppressive medications or NSAIDS within past 30 days (except low-dose \[81 mg daily\] aspirin). * No significant underlying diseases that could potentially interfere with the immune assays or cardiac or renal or liver problems. * History of blood clot or hypercoagulable state or GI bleed/ulceration.