Blue Light Therapy

What is Blue Light Therapy? 

Blue Light Therapy, also known as Photodynamic Therapy (PDT), is a non-invasive, well tolerated method to treat actinic keratoses (AKs), which are precancerous skin growths. 

One treatment cycle consists of 2 blue light treatments separated by 4-8 weeks. To get the maximum benefit, both treatments must be completed.

It usually takes 1 week or less for your skin to appear back to normal after treatment.  

PDT has 2 steps:

1.     A medication called aminolevulinic acid (ALA) will be applied to the affected skin to sensitize it to light. 

2.    A blue light will be shined on the area, which will react with the medication and destroy the AKs.


  • Thoroughly wash hair and the area being treated the night before your appointment.

  • Shave the area that is being treated if your provider has advised you to do this (hands, forearms, face, etc.) at least 1 day BEFORE the appointment.

  • 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 and over the counter:

o   Retinoids (compounds found in eye creams, serums, and moisturizers)

o   Vitamins, Herbal/Dietary supplements

o   Antibiotics or if you were recently taking an antibiotic

  • 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 (ALA) 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 your treatment.

·       If you have a history of herpes, take Valtrex (valacyclovir) as instructed by your healthcare provider.

·       Bring something to protect the treatment area from the weather and sun: wide brim hat, umbrella, sunglasses, long sleeved shirt, long pants, scarf, etc.


·       Acetone or alcohol will be applied to clean and prepare the treatment area.

·       A medication called 5-aminolevulinic acid (ALA) will be applied to the treatment area to make it sensitive to sunlight. You will wait 1-2 hours in the office for the medication to be absorbed by the precancerous cells.

·       A blue light will be shined on the treatment area for about 17 minutes which will activate the medication. You will be given eye protection to wear during the light treatment. 

·       During the treatment, you may experience some discomfort. It may feel like a stinging, prickling, or burning sensation, similar to a sunburn. This usually goes away after treatment but may take up to 48 hours to go away completely. 


Everyone responds differently to this treatment. For 1 to 2 weeks post treatment, you may experience the following:

• Redness that feels like sunburn

• Slight swelling

• Peeling, scaling, crusting

• itching, tingling

• Oozing


·       Apply a cool compress (cold cloth or ice pack) a few times a day for the first 24 hours.

·       The day after your treatment, use a gentle, fragrance-free cleanser (such as Cetaphil, Cerave, Dove, or Eucerin) to clean the treated area. Use a clean towel to pat skin dry and avoid rubbing the area. Then apply a moisturizer (such as Cetaphil, Cerave, Lubriderm, Aquaphor, or Vaseline) to the area to keep the skin moist. 

o   Storing your moisturizer in the refrigerator can increase the cooling effect.

·       If you have discomfort after the treatment, take an over the counter medication such as acetaminophen (Tylenol), ibuprofen (Advil, Motrin), or aspirin. If you are allergic to these or cannot take them to due a medical condition, ask your healthcare provider about which medication to take. 

·       You can also take an antihistamine (such as Benadryl) to help with any itching or swelling. Talk to your healthcare provider before taking this. 

·       For 48 hours after treatment, you must avoid bright light including:

o   Direct AND indirect sunlight

o   Very bright indoor lights (spotlights, medical exam lights). Normal house lighting is okay.

o   Blue light—Do not sit very close to a bright computer or TV 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 can’t cover the treated area, use a broad-spectrum sunscreen at least 30 SPF. 

·       Even after 48 hours, continue to use sunscreen. 

·       If a scab forms on the treated area, do not remove or pick at it. 

·       Return for a follow-up appointment as instructed by your doctor.