Photodynamic Therapy (Blue Light)

What is photodynamic therapy (blue light)?

Photodynamic therapy (PDT or blue light) kills cancer cells by using a combination of a light-sensitizing drug and a very bright light. One treatment consists of two blue light treatments roughly four weeks apart. To get the maximum benefit, both treatments must be completed. It is a two-step process consisting of the application of the medication called Aminolevulinic Acid (ALA) that will sensitize the area to light and the shining of the blue light that will activate the medication and destroy the precancerous lesions.    

Preparing for your treatment 

  • If you have an active COLD SORE in the treatment area, please call and RESCHEDULE. 
  • Plan to be at your appointment for 2-3 hours.  
  • Let us know if you: Take any medications, both prescription or over-the-counter: Retinoids, Antibiotics currently or recently 
  • Currently have or have a history of oral (cold sores) or genital herpes 
  • Have Porphyria, a rare disorder that makes your skin sensitive to the sun 
  • Are allergic to 5-Aminolevulinic Acid or Soy 
  • Are pregnant or plan to become pregnant  

On the day of your treatment

  • DO NOT apply creams, lotions, or makeup on the area being treated.
  • DO NOT shave the area being treated on the day of treatment. 
  • If you have a history of Herpes, take Valtrex (Valacyclovir) as instructed by your provider.
  • Bring something to protect the treatment area from the sun: a wide-brimmed hat, umbrella, long sleeve shirt, long pants, scarf, etc.  
  • Bring something to read.

During the treatment

  • The area will buffed.
  • The area will be scrubbed vigorously with Acetone.
  • ALA will be applied. The medication will soak into your skin for 1-2 hours. This allows appropriate time for the medication to be absorbed by the precancerous cells. You do not have to wait in the office after the medication has been applied; you are free to run errands until your incubation time is up. 
  • You will be placed under the blue light for 16 minutes and 40 seconds. This activates the medication. During this time, it is normal to experience some discomfort. It may feel like stinging, prickling, or a burning sensation.      

After your treatment

  • Everyone responds differently to this treatment due to the different extent of sun damage. For one to two weeks post treatment, you may experience the following: 
  • Redness that feels like a sunburn 
  • Slight swelling 
  • Peeling, scaling, crusting Itching, tingling 
  • Oozing  

Homecare instructions

  • Apply a cool compress (cold cloth or ice pack) a few times a day for the first 24 hours, or longer if needed 
  • The day after treatment, use a gentle fragrance-free cleanser (such as Elta MD, Cetaphil, CeraVe, Dove, or Eucerin) to clean the treated area. Use a clean towel to pat dry; avoid rubbing the area. Then, apply a moisturizer (such as Elta MD, Cetaphil, CeraVe, Lubriderm, Aquaphor, Solarcaine, or Vaseline) to the area to keep the skin moist. Storing the moisturizer in the refrigerator can increase the cooling effect.  
  • If you have discomfort after the treatment, you can take over-the-counter medications such as Tylenol or Ibuprofen. If you are allergic to these or cannot take them due to a medical condition, ask your provider about an alternative medication. 
  • You can take an antihistamine (such as Benadryl) to help with swelling and itching. Talk to your provider before taking this. 
  • For 48 hours after treatment, you must avoid bright lights, including: 
  • Direct AND indirect sunlight 
  • Very bright indoor lights (spotlights, medical exam lights). Normal house lighting is okay 
  • Blue Light. Do not sit too close to your computer screen or television screen 
  • For 72 hours after treatment, wear a hat, scarf, long-sleeved shirt, and or long pants if you need to leave your house 
  • If you must be outside after treatment, protect the treated area from the sun. If you cannot cover the treated area, use a broad-spectrum sunscreen of at least SPF 30 
  • Even after 48 hours, continue to use sunscreen. 
  • If scabs form on the treated area, do not remove or pick at them 
  • Return for a follow-up appointment as instructed by your provider

Please call if you have:

  • Fever of 100.4 or greater 
  • More than two weeks of redness, swelling, scaling, cracking, crusting, tingling, oozing, or draining. 
  • Mild Flu-like symptoms that get worse or will not go away 
  • Worsening pain or pain that persists 
  • Blisters or open sores on the treated area 
  • Any other unexpected problems or questions 


For any questions regarding PDT/Blue light, contact us or schedule an appointment online