- Photodynamic therapy is a treatment system which combines the use of Levulan, a light sensitive substance, and a light or laser source: BLU-U, PDL or IPL, LEDs which activates it in order to destroy unwanted cells.
- Levulan is a 20% 5-aminolevulinic acid (ALA) solution, a natural substance found in all humans. In the body, it functions as a precursor to hemoglobin, a crucial component in the manufacturing of red blood cells
- When applied to the skin for an hour or more, Levulan starts converting to a powerful photo sensitizer called Protoporphyrin IX (PpIX). PpIX accumulates preferentially in fast growing cells such as precancerous cells, as well as the sebaceous glands where acne bacteria thrive, hence its success in treating both actinic keratoses and acne. The longer the application, the more PpIX is accumulated. When a sufficient concentration has been achieved, a light or laser beam activates it. This produces a salvo of oxygen singlets that not only destroy the precancerous cells and acne causing bacteria, but also shrink the size of the sebaceous glands.
- PDT of any method always makes the skin highly photosensitive for the next 48 hours. This means: full continuous opaque sun protection of all treated areas and avoidance of light exposure for 2 days.
PDT for actinic keratoses
Patients can choose one of two options.
- The first one is done in a single session by leaving the Levulan on overnight before the Blu-U light activation. This is an uncomfortable treatment and requires a week of down time for the redness and peeling to resolve. The advantages include: single treatment, high efficacy rate and less temporary disfigurement than Efudex and Aldara cream treatments.
- The second one involves three sessions, a month apart, of a 1 hour Levulan application in our office, followed by light activation. This treatment is very comfortable, usually causes no down time. ALA/PDT is very helpful in those unwilling or unable to go through long topical treatments. Residual lesions may persist and require individual treatment with a cream.
PDT for acne
- ALA/PDT works best in patients who have inflammatory acne, not just blackheads and whiteheads. As a matter of fact, a pustular follicular reaction to the treatments has been shown to lead to the most significant improvement.
- Following a thorough cleansing and a Vibradermabrasion to enhance penetration, the ALA is applied to all acne prone areas and left in place for 45 to 60 minutes. The ALA is then activated with a sequence of different light sources.
- A treatment course usually involves at least 3 sessions, a month apart. Occasional boosters are recommended to maintain improvement. About 60% of patients achieve near clearance after 3 treatments. 30% require 2 or 3 treatment courses.
- ALA/PDT compares favorably with oral antibiotics. It is helpful for patients who are not compliant with or non-responding to their traditional treatment. It offers another option for patients unwilling or unable to take internal medications.
- ALA/PDT is safe, effective, has no systemic side effects and avoids problems with drug resistance.
- Patients should not stop their creams. Studies have shown over and over that the combination of light and surface treatments generates superior results than either one alone. Topical retinoids especially will help maintain results and stimulate the pore lining not to plug up again.
Other uses for PDT
- ALA/PDT has repeatedly shown to boost the results of IPL photofacial rejuvenation
- Extensive sebaceous hyperplasia
- Reduction in pore size especially associated with rosacea.