Photodynamic Therapy (PDT) for Actinic Keratoses

Actinic keratoses (AKs) are rough-textured, dry, scaly patches on the skin that are caused by too much exposure with ultraviolet light such as sunlight and tanning beds. You may refer to them as sun spots. AKs most often show up the face, scalp, and ears. Varying in color from skin toned to reddish brown, actinic keratoses can be as small as a pinhead or larger than a quarter.

Actinic keratoses develop over time due to years of sun damage. Even if you never spent much time in the sun, simple tasks such as going from your car to the grocery store or watering your plants outside without sunscreen add up and increase your risk for developing AKs. AKs take a long time to develop and usually appear after the age of 40. Your risk of developing AKs increases if you have one or more of the following risk factors: a history of cumulative sun exposure, fair skin, blonde or red hair (in particular if combined with blue, hazel or green eyes), a tendency to freckle or burn after sun exposure, and a weakened immune system.

Actinic keratoses are the most common precancer. They are capable of turning into squamous cell carcinoma (SCC). About 10 percent do develop into SCC within just a couple of years. Since we don’t know which AKs will turn into squamous cell carcinoma, it is imperative for those with AKs to regularly be seen by a dermatologist. Repeated skin checks are important for early detection and prevention. Actinic keratoses can be treated with liquid nitrogen for individual lesions. If field therapy is needed, patients can be treated with topical cream or photodynamic light therapy. At Susan H Weinkle, MD’s office, we offer all modalities to treat your AKs.

Photodynamic therapy (PDT) is a cancer and pre-cancer regimen that uses certain medications called photosensitizing agents (Levulan Kerastick), together with Blu-U blue light to obliterate the cancer cells on the surface of the skin. When you come in to receive your PDT, our nurse practitioner will apply the Levulan Kerastick topical solution to your AK lesions. Next you’ll have to wait the recommended time in order to allow the solution to penetrate the targeted cells. We recommend you take come Tylenol or Advil while waiting. After that waiting period, you will return for a second part of the treatment which includes illuminating your treated lesions with the Blu-U blue light. During this blue light treatment you may experience some stinging or burning, but this is normal and should feel better between 1 minute and 24 hours after the blue light is turned off.

After your PDT it is very important that you avoid sunlight and any other bright lights for at least 40 hours after the Levula Kerastick topical solution has been applied. Some examples of bright light to stay away from include tanning beds, household lights at close distance, exam room lights, the beach, and anything else that light can reflects off. Sunscreens with a physical blocker such as zinc oxide or titanium dioxide are necessary to protect against photosensitivity reactions caused by visible light during this time. Dr. Weinkle recommends Neutrogena Sheer Zinz SPF 50.

Common side effects may occur during and after your PDT. These side effects include burning and/or stinging, which may last up to 24 hours after your Blu-U treatment. Redness and swelling may also occur, as well as scaling and crusting. Moisturizers should help provide some relief during this time. There are pros and cons to PDTs. There are many studies that have proven PDT to work as well as surgery or radiation therapy in taking care of certain types of cancers and pre-cancers. Some advantages include:

  • No long term side effects
  • Minimally invasive
  • Outpatient procedure
  • A field treatment, treating a large area and sub-clinical lesions
  • Same site can receive multiple treatments, if necessary
  • Less expensive than other cancer treatments

Some disadvantages include:

  • PDT can only treat areas where the light can reach and can’t be used to treat large cancers or cancers that have grown deep into the skin.
  • PDTs cannot be used to treat cancers that have spread to other organs in your body.
  • The drugs used for PDT usually make people sensitive to light afterwards, so special precautions need to be taken such as staying indoors, avoiding the beach,, and anything else that light might reflect off of.
  • PDT cannot be used in people who have certain blood diseases, such as any of the porphyrias (a rare group of diseases that affect the skin or nervous system) or people who are allergic to porphyrias in the past.

To find out more information about PDTs, or if you have AKs that are concerning, please contact Susan H Weinkle, MD: (941) 794-5432. We look forward to seeing you soon.