Photodynamic Light therapy (PDT)

May 6, 2019

Photodynamic Light therapy (PDT)

Here at Paradise Dermatology, we utilize Photodynamic therapy (PDT) to treat actinic keratosis. An actinic keratosis (AK), also known as a solar keratosis, is a crusty, scaly growth caused by damage from exposure to ultraviolet (UV) radiation. An AK is considered a precancer because if left alone, it could develop into a skin cancer, most often the second most common form of the disease, squamous cell carcinoma.

Photodynamic therapy (PDT) is a procedure that uses special drugs, called photosensitizing agents, along with light to destroy cancer cells. The drugs only work after they have been “turned on” by certain kinds of light.

What is treatment like?

Aminolevulinic acid (Levulan Kerastick) is a solution that’s put right on the spots (called lesions) of actinic keratosis.

The drug is left on the affected skin anywhere from 1-4 hours. At that time, the area being treated will be exposed to a blue light for about 16 minutes. During the light therapy you will wear protective eyewear. You may feel stinging or burning once the area is exposed to the blue light, but it should go away within a day or so. The treated area may get red and scale and crust for up to 4 weeks before healing. If a lesion does not completely go away after treatment, it can be treated again 8 weeks later.

Who should not get treated with aminolevulinic acid?

Aminolevulinic acid is NOT recommended for people with skin sensitivity to blue light, people with porphyria, or anyone with an allergy to porphyrins.

Possible side effects

Photosensitivity reactions: Reactions caused by light can show up on the skin where the drug is applied. They usually involve redness and a tingling or burning sensation. For about 2 days after the drug is used, you should take care to not expose treated areas to light.

  • Stay out of strong, direct light.
  • Stay indoors as much as possible.
  • Wear protective clothing and wide-brimmed hats to avoid sunlight when outdoors.
  • Avoid beaches, snow, light colored concrete, or other surfaces where strong light may be reflected.
  • Sunscreens will not protect the skin from photosensitivity reactions.

Skin changes: The treated skin will likely turn red and may swell after treatment. This usually peaks about a day after treatment and gets better within a week. It should be gone about 4 weeks after treatment.

Other Indications for PDT

Acne vulgaris – The use of blue light alone is FDA approved for the treatment of moderate inflammatory acne vulgaris. It has been shown to aid in reducing the bacteria, P. Acne, that leads to break outs.