Pulse oximeter as a cause of skin burn during photodynamic therapy.

Photodynamic therapy is increasingly being used for the treatment of various cancers. However, this technique has a major adverse effect, namely skin photosensitization. An unusual case of skin burn associated with pulse oximetry during photodynamic therapy in a patient treated for an early esophageal tumor is described. The patient, who was treated with mTHPC, suffered a second-degree burn on the index finger with subsequent loss of the nail. The only previously reported case of such a complication occurred with Photofrin, whereby no tissue other than skin was damaged.