Topical photodynamic therapy in dermatology.

ALA-PDT is an effective therapy for non-hyperkeratotic facial actinic keratoses, Bowen's disease and superficial basal cell carcinoma. Additional applications remain at the experimental stage, with early potential suggested in acne and refractory warts. PDT offers the advantages of being non-invasive, well tolerated in slow healing sites, and tissue sparing, leaving the skin surrounding the tumour intact and functional. ALA-PDT may be particularly useful for large superficial tumours and for lesions in anatomical sites where disfigurement from conventional therapies may be a particular risk. The development of powerful filtered non-laser sources, along with the topical application of photosensitizer, makes ALA-PDT a more easily accessible therapy.