This information will help you prepare for photodynamic therapy, or PDT. 

PDT is an effective treatment for precancerous skin lesions called actinic keratoses. They are the first step in the development of skin cancer.

PDT is a two-step process. First, a medication will be put on the treatment area to make it very sensitive to light. You must wait while the medication is being absorbed. This takes 2 to 3 hours. Then, a red or blue light will be shined on the area. The light reacts with the medication and destroys the actinic keratoses.

Preparing for Your Treatment

  • Tell your doctor or nurse:
    • If you are taking any other medications or have changed medications. Some may change the way PDT works. Include the following:
      • Medications that require a prescription
      • Medications that do not require a prescription
      • Herbal remedies or supplements
      • Vitamins
      • Dietary supplements
    • If you have porphyria, a rare disorder that makes your skin sensitive to the sun
    • If you have an allergy to peanut or almond oil. We may not be able to treat you with PDT because it may not be safe for you
    • If you are pregnant or plan to become pregnant. This medication has not been used with pregnant women, so we do not know if it is safe

The Day of Your Treatment

  • Do not use creams, lotions, or make-up on the area to be treated.
  • Bring something to protect the treatment area from the sun. If it is on your face, bring a wide-brimmed hat or umbrella. If it is not on your face, wear clothing that covers the area.

During Your Treatment

  • The medication will be applied to the treatment area. Your doctor will tell you how long it will take for the medication to be absorbed.
  • During the light treatment, you may have some discomfort. Patients describe it as stinging, prickling, or burning sensations. This usually goes away after treatment, but may take up to 24 hours.

After Your Treatment

Each patient responds differently to this treatment. For a few days, you may have the following symptoms:

  • Redness that feels like a sunburn
  • Slight swelling
  • Peeling
  • Scaling
  • Crusting
  • Tingling
  • Oozing
  • Mild flu-like symptoms

Follow the guidelines below to help you manage these symptoms:

  • Apply a cool compress to the treated area for 24 hours. This will help reduce discomfort. To do this, take a clean washcloth, dip it into room temperature or cool water, ring it out, and apply it to the treated area. When the cool sensation goes away, soak the cloth again and repeat.
  • Take an over-the-counter pain medication. Some examples are acetaminophen (Tylenol®), ibuprofen (Advil®, Motrin®), and aspirin. Follow the directions on the bottle.
  • For 48 hours after your treatment, do not expose the treated area to bright light. This includes:
    • Direct sunlight
    • Indirect sunlight
    • Very bright indoor lights
  • Normal house lighting is okay. If you must be outside after your treatment, protect the treated area from the sun. If you can't cover it, use a broad-spectrum sunscreen with an SPF of at least 30 directly on the area. Broad spectrum means it protects against both UVA and UVB rays. If the area is on your face, wear a wide brimmed hat.
  • After 48 hours, use a broad-spectrum sunscreen with an SPF of at least 30 on the treated area. 
  • Starting the day after your treatment, use a gentle, fragrance-free cleanser to clean the treated area. Examples are Cetaphil®, Dove®, Basis®, and Eucerin®. Then, apply a moisturizer, such as Cetaphil®, Lubriderm®, Aquaphor®, or petroleum to the area to keep your skin moist.
  • If a scab forms on the treated area, do not remove or pick at it.
  • Return to the office for your follow-up appointment according to your doctor's instructions.