Photodynamic therapy (PDT) involves the use of a topical photosensitizer (20% solution of 5-aminolevulinic acid) and a light source to activate the photosensitizer. Once activated by light, the 5-aminolevulinic acid is transformed into protoporphyrin IX. Protoporphyrin IX is absorbed into sun damaged skin cells and sebaceous glands (oil glands of the face).
PDT can be used for the treatment of:
- Actinic keratoses
- Disseminated actinic porokeratosis
What to expect:
- The 5-aminolevulinic acid is applied to the treated area and allowed to incubate.
- After the incubation the light treatment will be applied.
- Once the treatment is completed, the area treated will be red and irritated.
- After treatment, it is critical to avoid sun exposure for 48 hours and apply a sunscreen with a minimum of SPF 30.
Photodynamic therapy (PDT) is a two-stage treatment that combines light energy with a drug (photosensitizer) designed to destroy cancerous and precancerous cells after light activation. Photosensitizers are activated by a specific wavelength of light energy, usually from a light source. The photosensitizer is nontoxic until it is activated by light. However, after light activation, the photosensitizer becomes toxic to the targeted tissue.
What dermatologic conditions can PDT be used for? PDT is FDA approved for the treatment of actinic keratoses (pre-skin cancers). PDT can be used off-label for a variety of skin conditions, such as acne and disseminated superficial actinic porokeratosis.
What does the skin look like after treatment?
The treated area of the skin is usually quite red and may appear to be flaking or peeling, as it would after a mild sunburn. The redness, and perhaps some of the flaking, can last for several days to a week or even two weeks. (After that, skin returns to normal.)
The area will also be more sensitive to light, so patients should not let any sunlight or very bright indoor lights hit the treated area for 48 hours after the procedure. After two days of keeping the area covered and protected from sunlight, you can go back to their normal activities—of course, using sunblock as needed for outdoor activity. Most patients tolerate the procedure very well, with only moderate downtime.
What else should you know about photodynamic therapy?
Photodynamic therapy doesn't just treat the lesions that you can see. This field therapy can treat existing spots and the earliest spots of sun damage that haven’t yet been diagnosed as actinic keratosis. There is evidence that photodynamic therapy can decrease a patient's risk of developing skin cancer in the future. It is likely that patients with a high level of sun damage will need further treatments and close follow up with their dermatologist.
About the procedure:
Photodynamic therapy is a procedure to treat actinic keratosis
(precancerous pink scaly areas caused by the sun), acne and aging skin.
Photodynamic therapy uses a topical photosensitiving agent called Levulan
(Aminolevulinic acid) that is absorbed into damaged or precancerous cells
in the skin. It is then activated by a blue or red light or a laser to shed
and peel sun damaged cells.
What to expect:
Plan to be in our office for 1.5-2 hours. Levulan solution will be applied
to your skin and will sit for about an hour. Bring a book and a hat.
After the incubation time, you will wash your face and sit under the light
for 4-10 minutes depending on the light source. This is the part that can
hurt. You will feel a burning or stinging sensation.
Post procedure you will be red and sometimes a little swollen. Your skin
stays red for 3-5 days and then starts to peel. Usually you are fully
recovered by day 7, however some people continue to peel for 2 weeks.
You are photosensitive for 48 hours post treatment. Any light exposure,
even ambient light, can significantly increase the reaction and peeling. We
recommend staying indoors and using zinc or titanium oxide sunscreen for 48
hours. After 48 hours we recommend limiting sun and using physical block
sunscreen until your skin has fully peeled.
Post treatment we recommend you wash the area twice daily with a gentle
cleanser and use either Vaseline or Aquaphor several times a day.