Photodynamic Therapy (PDT)

Photodynamic therapy (PDT) or “blue light” treatment is quick and effective treatment for the precancerous growths known as actinic keratoses. 

How Photodynamic Therapy Works

The technology of PDT is based upon the photosensitization of a chemical normally produced in the body called protoporphyrin IX. Normally, this highly photosensitizing chemical is produced as the body makes blood but is rapidly converted into non-sensitizing products. The medicine used in PDT, called amino-levulinic acid (ALA) is a pro-drug that converts to protoporphyrin IX after application to the skin.  The medicine accumulates in the precancerous cells, causing them to be sensitive to visible light in the blue spectrum. A specialized light source is then applied to the skin, causing the cells that took up the medicine to be destroyed. Since the medicine accumulates more readily in the pre-cancerous cells, this is a targeted treatment directed only at sun damaged cells in your skin. 

What to Expect During Photodynamic Therapy

When you come in for Photodynamic Therapy, it’s a good idea to cleanse your face beforehand and remove all makeup. This will make it easier for the medicine to be absorbed into the skin. The provider will cleanse the treatment area before applying the ALA medicine. This is a liquid in an alcohol base and the application is typically painless. The medicine is then allowed to incubate on the skin for a provider-determined amount of time. This time ranges from 1 to 4 hours depending on the area being treated. After incubation, the blue light is applied to the skin. The light session is short, taking approximately 17 minutes. During the treatment, you will be seated in a comfortable chair, in front of the machine. Once the protective eyewear has been placed over your eyes, the machine will be turned on and the fluorescent light will be administered to your skin. Patients typically experience mild stinging during the first minutes. The severity of the stinging is different for each patient but is related to the amount of sun damage on the skin. Most patients tolerate any associated discomfort very well, without the need for topical anesthetics. After treatment, you should strictly avoid direct sun exposure to the treated skin, as it remains sensitive to light. Depending on the intensity of the treatment, some patients may experience redness and skin irritation for 24-48 hours after treatment. In some cases, scaling and crusting can occur, and gentle emollients such as aloe or Aquaphor should be applied to the treatment area. To learn more about Photodynamic Therapy or to schedule a consultation, please call Juniper Dermatology today.