Photodynamic therapy (PDT) is a medical treatment that makes use of a photosensitizer and a light source to activate the administered drug, in order to kill the unwanted cells in the body, mostly cancerous or precancerous cells. In dermatology, PDT is FDA approved for treatment of non hyperkeratotic actinic keratosis of face and scalp.
Equipped with blue light therapy (BLU-U®) together with photosensitizer 20% Aminolevulinic acid (ALA), as one of the options for treatment of actinic keratosis and sun damaged skin.
What’s Good about PDT?
1. Good Response Rate
Clearance rate of actinic keratosis following PDT is comparable to other treatments like cryotherapy and immunotherapy like topical 5-FU cream (Efudix), and even superior to topical imiquimod (Aldara). In clinical trials, PDT achieved complete clearing of all actinic keratosis lesions with 1 treatment in more than 70% of patients at 12 weeks. With 1 or 2 treatments, 88% of patients had 75% or more of the actinic keratosis cleared.
2. Cosmetically Favourable
Compared with other procedures like cryotherapy which can result in hypopigmentation or even scarring, PDT achieves better cosmetic outcome and better patient satisfaction.
3. Subclinical Actinic Keratosis Clearance
PDT provides field treatment, that is treating the whole area of sun damaged skin therefore eradicating those subclinical precancerous actinic keratosis (i.e. those not apparent lesions) at the same time.
How is PDT Done?
- If you are having photosensitive medical conditions, for example systemic lupus erythematosus or porphyria, you are not a good candidate for such procedures.
- The treated area will be washed and subsequently go thru microdermabrasion.
- 20% ALA will be applied by the doctor and then covered, and wait for 30min up to 4hrs to be absorbed (incubation).
- The ALA covered skin will then be washed and illuminated with Blu-U for about 17 minutes but may vary on doctor’s decision. There may be sensations of warmth, tingling, heat or burning; cool air or fan maybe used during the treatment to ease the discomfort.
- You have to completely stay out of the sun for 48 hours after the procedure, with sunglasses, masks, and long sleeves if arms are treated when you leave the clinic. And sunscreen is recommended at all times after the treatment.
- The treated skin will be red and swollen, followed by peeling for about 7 to 10 days. You may experience bronzing (like suntan) for few weeks afterwards, and it is more likely in darker skin or tanned skin.
- You will be reviewed about 4 weeks later to see the progress. Sometimes a second treatment might be needed.