Mainstream uses for photodynamic therapy (PDT) in dermatology include nonmelanoma skin cancer and its precursors, acne vulgaris, photorejuvenation, and hidradenitis suppurativa. Many other dermatologic entities have been treated with PDT, including psoriasis, lichen planus, lichen sclerosus, scleroderma, cutaneous T cell lymphoma, alopecia areata, verruca vulgaris, Darier's disease and tinea infections. Nondermatologic applications include anal and vulva carcinoma, palliation of metastatic breast cancer to skin, Barrett's esophagus, and macular degeneration of the retina. PDT also has found to be useful in immunologic and inflammatory disorders, neoplasias other than skin cancer, and infections. The ability of this treatment to hone in on dysplastic epithelial and endothelial cells while retaining viability of surrounding tissue is its key feature because this leads to specific tumor destruction with cosmesis and function of the target organ intact.