Click Here To Schedule A Consultation

Schedule a Consultation

  • This field is for validation purposes and should be left unchanged.

What is Photodynamic Therapy?

Photodynamic therapy is a unique noninvasive treatment which utilizes light treatments along with a photosensitizing molecule to treat the skin.  Photodynamic therapy is also referred to as PDT or Blue Light Therapy. PDT is used to treat a wide range of skin conditions in dermatology.  PDT was originally FDA approved for the specific treatment of actinic keratoses on the face and scalp. Now, PDT has been used as an extremely effective treatment for acne vulgaris, acne scars, and other skin disorders. Many patients suffer from acne or acne scars, and topical acne treatments have been ineffective.  Many acne vulgaris patients do not want to be on long term oral antibiotics and prefer this noninvasive photodynamic therapy for the treatment of their acne.  In addition, some people suffer from severe acne and are not candidates for oral medications, such as isotretinoin (Accutane) therapy. For these patients, photodynamic therapy can be performed in a dermatologist’s office with safe and highly effective results.

How does PDT or photodynamic therapy work for acne vulgaris?

While PDT was originally approved by the FDA for the treatment of actinic keratoses, after various clinical trials, it was determined that PDT is a safe and effective way for treating acne vulgaris, cystic acne, acne scars, and severe acne. PDT works by shrinking the skin’s oil glands and reducing its oil production.  By reducing the oil in the sebaceous glands, it reduces the sebum production, and the result is that the pores are not clogged.  It further decreases the number of comedones produced and the overall number of pimples and comedonal acne lesions. PDT’s mechanism of action is that it causes a phototoxic damage to sebaceous glands and hair follicles.  PDT for acne vulgaris has been proven to be a safe and effective treatment for patients with severe acne who do not respond to traditional topical acne treatments. ALA-PDT (5-aminilevulinic acid with PDT) has also been used for patients who have severe acne for whom isotretinoin (Accutane) is not an option.  In addition, ALA-PDT has been proven to kill the bacteria, p.acnes, which causes acne.  Photodynamic therapy not only reduces the acne, but improves the skin’s overall texture, and the appearance of acne scars.

Photodynamic therapy for acne usually begins with microdermabrasion to remove the dead skin cells on the surface of the skin.  Having microdermabrasion before the levulan is applied allows the medication to have better penetration.  Levulan is then applied to the skin for 15 to 60 minutes, and later removed thoroughly with water.  The patient is positioned to sit in front of the Blu-U and has blue light therapy for approximately 16 minutes.

A series of three to five PDT treatments are typically performed in a period of two to four-week intervals. The number of PDT treatments will be determined during your consultation and based on the severity of your acne. Most patients see improvement in their acne after a single treatment but the rest results come with the full course of treatment.

What is the process of PDT?

Photodynamic therapy works by utilizing a photosensitizing molecule and a light source which activates this medication.  There are different photosensitizes used such as Levulan or 5-aminolevulinic acid , and methyl aminolevulinate (MAL-PDT). The photosensitive molecule which Dr. Green utilizes is called Levulan. Photodymaic therapy is a three part treatment process. First is the application of photosensitive drug, second is the incubation period involved, and last the light activation.

Step 1:  Application of photosensitive drug

The patient comes to the office and the treatment area is cleaned of any moisturizers or sunscreens. Alcohol may be used before your treatment to remove any makeup or oils from your face. Pre-treatment photographs are taken for your patient record and procedure consents are removed and signed. To begin the treatment the photosensitizer, Levulan Kerastick Topical solution (20% delta-aminolevulinic acid HCL), is applied to the treated area, which is typically the face.  Other areas such as the back, chest, or scalp, can be treated as well. The medicine is allowed to air dry for a few minutes and then patients wait in the office for an hour or more for the Levulan to incubate.

Step 2:  Incubation time

The incubation time for Levulan is typically one hour on the treatment area. Levulan is a clear liquid which is applied and there is no discomfort during this incubation period.  The incubation period for the face is 15 to 60 minutes. Other areas of the body can have longer incubation times. Some areas such as the back, chest, arms, or legs, may need incubation times of more than one hour.

Step 3:  Light Activation

The levulan is removed completely with water. There are many different PDT light sources, which include laser light, intensed pulsed light, blue light, red light, and visible lights including natural sunlight. The patient sits in front of the UV light, most commonly blue light (BLU-U) is used.  The light source needs to be directly applied to the treatment area where the photosensitized medication was applied.  With BLU-U, typically the treatment area is six inches away from the light source.  The patient sits in front of the blue light for approximately 16 minutes while the Levulan is activated by the light source.  Most patients prefer to sit up in a comfortable chair facing the BLU-U light when treating the face.  When treating other areas such as the legs, you can lie down on the exam table to complete your treatment. Eye shields are worn during the procedure to help protect your eyes from the UV light.

Levulan can cause sun sensitivity to the treated area for 24-72 hours after exposure.  It does not cause sun sensitivity on other parts of the body where the Levulan was not applied.  It is best to avoid direct light or sun light to your treatment area for 24-72 hours after your procedure. Sun glasses and a wide brimmed hat, as well as sunscreen, are recommended.

What are the side effects of photodynamic therapy?

The possible side effects of photodynamic therapy include redness, edema, crusting, irritation, swelling or peeling of the treatment area. It can feel very similar to a sunburn which resolves quickly.  There can also be temporary hyperpigmentation in patents with darker skin tones.

Approximately 50% of patents experience stinging or burning during the treatments.  This burning usually plateaus within 5 to 6 minutes of treatment.  We often apply a fan to cool the area during the treatment to improve patient comfort.

Who is a good candidate for PDT in dermatology?

35-44 year old man treated with photodynamic therapy to remove red spots

Results with ALA-PDT photodynamic therapy are impressive.  For patients with acne vulgaris who are non responding to topical or oral antibiotics, photodynamic therapy is a great option.  It can be performed on all skin types with minimal side effects.  ALA-PDT treats the active acne lesions, active pimples, decreases comedonal acne, kills the bacteria which cause acne and improves the appearance of acne scars.  Again, it is a very popular alternative for many patients who are reluctant to take oral medications or unable to take isotretinoin (Accutane) and want to avoid systemic side effects.  Photodynamic therapy will leave your skin smooth and reduce both acne and acne scars on your face.

In addition, patients who have had chronic sun damage and many pre-cancers, benefit with ALA-PDT as it treats and removes actinic keratosis and the surrounding sun damaged skin. Most patients prefer photodynamic therapy over Efudex cream to treat actinic keratosis, since the cream needs to be used for several weeks and leaves patients red, sore, and scaly for a prolonged period of time, rather than the typical 48 hours from photodynamic therapy.  The other huge advantage of photodynamic therapy over spot treatment of actinic keratoses, is that the entire face can be treated in one session. The entire face will be treated, leaving even, rejuvenated skin, treating the entire photo damaged area.  Unlike other spot treatments for the face, such as liquid nitrogen, there is no risk of hypopigmentation or scarring associated with ALA-PDT.  All skin types can be treated with photodynamic therapy.  However, care must be used in treating Fitzpatick skin types III or greater, as they have increased risk of temporary hyperpigmentation.

Photodynamic therapy can only be performed in a dermatology office. Since this treatment is more expensive than prescription medications, it is wise to check directly with your health insurance company to ascertain if they cover this treatment for your skin.

If you have any pre-existing photosensitive conditions, such as lupus erythematous or porphyria, it is best to tell Dr. Green before your procedure.

If you have an active herpetic or bacterial infection, it is best to let Dr. Green know before to prescribe the proper oral antivirals or antibacterial medications and possibly defer treatment until the condition resolves.

PDT / BLU-U for Actinic Keratoses and Skin Cancer

PDT is an elegant way to treat abnormal cells, or skin cancers from the face. PDT was originally FDA approved to treat skin cancer. The very superficial skin cancers are called actinic keratoses. The prompt treatment of these superficial pre-cancers prevents these abnormal cells from growing and transforming into deeper skin cancers.  PDT has also been used to treat other skin cancers such as basal cell carcinomas and squamous cell carcinomas.

PDT works by direct injury to the targeted abnormal cells.  Activated oxygen molecules are produced which injure or destroy precancerous lesions. Since the normal skin barrier is not present at the sites of the actinic keratoses, the photosensitizing molecules are absorbed by this sun damaged skin and are activated by light. These activated oxygen molecules, porphyrins, treat these actinic keratoses and leave the normal skin undamaged.  Several weeks after treatment it is important to follow-up with your dermatologist to ensure which areas were treated and see if any of the remaining areas need to be biopsied for possible deeper skin cancer.

Originally, Blue light or PDT was used for the treatment of actinic keratoses of the face and scalp.  Now, this method of treatment is utilized for the neck, chest, arms, legs, and trunk.

The number of treatments for actinic keratoses depends on the amount, number, and severity of your precancerous lesions. Typically 3 sessions are indicated, four weeks apart, with a greater number of treatments are advised in more severe cases.

How do I prepare for my treatment?

It is best to come into the office for your procedure without any makeup or sunscreen. You should continue your regular medications but can refrain from Retin-A or any exfoliating creams for a few days before your treatment. You should bring a wide brimmed hat and sun glasses to the appointment. If you are having your arms treated, you should wear a long-sleeve shirt and if your hands are being treated, bring gloves. You may also want to bring personal musical earphones to listen to music or a pod cast during your treatment time.  In addition, you will be advised to come to the office at least one hour before your scheduled treatment time for Dr. Green to apply the Levulan medication. If you are having an area which requires a longer incubation time, you may need to come to the office earlier. Patients are encouraged to avoid smoking for one week after the procedure as smoking delays wound healing.

Post Treatment Protocol

It is essential to avoid sun exposure for the first 48 hours after your PDT light treatment. Sunscreen is also an essential component after the treatment to prevent future sun damage and pre-cancers. Avoiding sunlight for the first 24 hours is critical to avoid getting an increased erythematous reaction to the treatment. Other sun protection includes wearing a wide brimmed hat and proper sun avoidance. Patients are advised not to go into saunas or steam rooms for the first few days and avoid using any exfoliating products, retinoids, or alpha hydroxy acid creams. Dr. Green also recommends applying gentle lotions or emollients for at least one week to the treated area. It is advised not to pick or scrub the skin after the procedure as this could lead to scarring or infection.  If patients feel any mild discomfort after the procedure, acetaminophen (Tylenol) or another mild pain reliever can be taken.

Patients are thrilled with this procedure as there is minimal downtime. Depending on the degree of actinic keratoses, the best treatment results may take three or more sessions.

PDT may also be combined at different periods with such treatments as Intense Pulsed LightV-Beam (pulsed dye laser), or Fraxel® Dual Laser, in order to remove sunspots, rosacea, and sun damage, and leave the skin as rejuvenated and beautiful as possible.  PDT has been described as a “super photo facial” when it is combined with intense pulsed light or IPL .


45-54 year old man treated with BLU-U light (2 weeks post treatment)

Who performs photodynamic therapy?

Only a licensed dermatologist can perform photodynamic therapy in a doctor’s office.  It is best to consult with a board certified dermatologist who is an expert in these treatments and laser therapy.

If you are concerned with your skin due to pimples, acne vulgaris, acne scars, sun damage, or actinic keratoses and sun damage, it is best to consult a board certified dermatologist, like Dr. Michele Green, who is an expert in acne, acne scars, rosacea, and sun damage treatment for your skin.  You can arrange a private consultation with Dr. Michele Green and discuss your best treatment options by calling 212-535-3088 or contacting us online today.

Related Topics

Call Us (212) 535-3088