Photodynamic therapy involves the pre-treatment with 8 aminolevulinic acid ( Levulan) before light treatment with the Blu-light or an equivalent light source. In other words the Levulan kerastick is applied to the intended area, there is an incuatiion period of one half hour and then a light treatment of approximately 16 minutes.
This has proven to be an excellent treatment for actinic keratosis. Typically, I use this in severe cases of actinic keratoses: either numerous actinic keratoses or actinic keratoses that are nearly becoming malignant ( squamous cell carcinomas).
This is an FDA approved treatment and is covered by insurance.
It is also being used for hidradenitis suppuritiva ( a condition of cysts in areas of apocrine glands such as the groin, armpits, breasts and curiously ears), psoriasis and even warts. Of course, these uses are off-label.
PDT is also used for photorejuvenation. Its effect is probably to a series of microdermabrasions, but since the cost is $180, this is less expensive and far more convenient ( one or two treatments opposed to six).
Now, for its use in acne. This works in a rather subtle manner. The bacteria that is incriminated as playing a villain role in acne ( though in actuality an otherwise harmless sort, P. acnes) produces a chemical called porphyins. The blue light is attracted to these porphyrins and zaps not only the porphyrins but the nearby bacteria. The 8 amino-levulinic acid is absorbed into the porphyrins and gives the blue light an extra punch. PDT used in this manner is about as effective as a good antibiotic. The kerastick costs about $104 ( though I think the company..DUSA.. recently raised their prices..so much for deflation) and the light treatment itself runs another $85.
I hope this explains PDT therapy.
