 Cosmetic Services > Photodynamic Therapy
Photodynamic Therapy (PDT)
Questions and Answers
What is photodynamic therapy?
Photodynamic therapy (PDT) refers to the application of a medicine to skin that is then activated by the application of light.
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What conditions are treated with photodynamic therapy?
PDT is used to treat acne and actinic keratosis (precancerous sun damage).
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How does photorejuvenation work?
First, a colorless liquid called amino-levulinic acid (also known as ALA, trade name: Levulan) is brushed onto the skin. This is left in place for 30-90 minutes, depending on the severity of the problem and the potency of the treatment that is required.
During this time, the ALA is converted to another natural chemical of the body (protoporphyrin IX referred to as Pp IX), and this accumulates in the cells of the skin. It accumulates to a greater degree in bacteria, sebaceous glands, and precancerous or cancerous cells. Also, the longer it is left on the skin, the greater the degree of absorption into the cells.
Following this incubation period, pulses of intense light are applied to the skin using our Harmony IPL device (IPL is short for Intense Pulsed Light). The intense light activates the Pp IX in the skin. The Pp IX turns into a "scavenger" molecule that kills the cells that have absorbed a lot of it (bacteria, sebaceous glands, precancerous or cancerous cells).
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What is amino-levulinic acid?
Amino-levulinic acid is a biochemical that exists naturally in the body. It is a building block for hemoglobin, the molecule that carries oxygen in the blood.
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What is IPL?
IPL is short for Intense Pulsed Light. As the name implies, IPL devices produce intense pulses of light from flash lamps. This light initially contains all colors of light in the visible spectrum plus infrared and ultraviolet. Because ultraviolet light is harmful, all IPL machines use some type of mechanism, usually filters, to block out UV.
Lasers are quite different, because they produce light of only one color (wavelength).
The fact that lasers and IPL are different is neither good nor bad. Their different properties simply make them useful for different tasks.
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What areas can be treated?
Any skin area can be treated with PDT, but the most common areas are the face, neck, upper chest, hands, and forearms. These are the areas that receive the most sun exposure and, hence, sun damage.
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Who is a good candidate for photodynamic therapy?
People with severe acne and actinic keratosis are good candidates for PDT.
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How are treatments done?
First, you will be given microdermabrasion to remove dead skin cells. Then, a colorless liquid called amino-levulinic acid (also known as ALA, trade name: Levulan) is brushed onto the skin. This is left in place for 30-90 minutes, depending on the severity of the problem and the potency of the treatment that is required.
Following this incubation period, pulses of intense light are applied to the skin using our Harmony IPL device to activate the biochemical. Intense pulses of light are applied to the skin using a hand piece that has a window about half an inch wide and one and a half inches long. This window is held against the skin and a single flash is given. The technician moves the window to the adjacent area of skin and another flash is delivered. The entire face can be covered in about ten minutes.
Following activation, the skin is cleansed to remove the active substance. Total block sunscreen is then applied. You must then go directly home and stay indoors with the curtains closed to avoid further activation of the biochemical by sunlight.
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How much does photorejuvenation hurt?
There is no simple answer to this question, because pain response and tolerance is different from person to person. Most people find that photorejuvenation causes mild to moderate pain.
The flashes are felt as heat and a mild-moderate sting. This level of energy will be enough to have therapeutic benefit, but not enough to cause any damage to the skin.
When ALA is left on the skin for prolonged periods, the discomfort may be greater.
There are several things that can be done to minimize discomfort including cooling, vibration, and topical anesthetics.
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What can I expect following photodynamic therapy?
Mild to marked redness is normal. It starts within hours and will last two to three days in most cases. In rare instances, it may persist for three weeks or so. There may be mild-moderate swelling.
There may be some pain for the first day or so, but this is usually mild and seldom requires medication. It feels like stinging or irritation. Tylenol or Advil can be used.
Peeling usually occurs, starting on day three or so and persists for about five days.
If there are precancerous or cancerous lesions in the treated areas, they will react more vigorously. In these areas, redness and peeling may last as long as three weeks. These areas may actually ulcerate and scab over.
Strict sun avoidance is required for 24 hours following treatment (see next question).
Patients may return to work immediately, but most people prefer to take a few days off.
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How should I care for my skin following treatment?
Strict sun avoidance is required for 24 hours following treatment. Sunlight will continue to activate the Pp IX and produce an excessively vigorous response. Any visible light will activate Pp IX. Most sunscreens do not prevent this further activation, because they filter out only UV light. Only total block sunscreens will work.
The skin will get very dry and start to peel, so moisturizers are helpful. Vaseline is recommended at night.
Resist the temptation to pick off the peeling skin. This may cause breakage of the skin and increase the risk for infection and scarring.
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What are the side effects of photodynamic therapy?
The intense light can cause burning and blistering, but this is very rare, especially with the Harmony IPL. Burns may result in permanent scarring.
Pigment changes can occur. This can be increased pigmentation or decreased pigmentation in the treated area. This is rare with the Harmony IPL. Pigment changes are almost always temporary, lasting perhaps a few months. They almost always occur when people expose themselves to sunlight following PDT. Increased pigmentation can be treated with creams. There is no treatment for decreased pigmentation.
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What makes the Harmony IPL different from other IPL machines?
First, read the question: What is IPL?
All IPL machines use some type of device to prevent harmful ultraviolet light from reaching the skin. Most machines use filters to simply block out the UV rays. In contrast, the Harmony IPL converts the UV light to useful wavelengths. This method is called Advanced Fluorescent Technology (AFT). Most of the energy boost occurs at the wavelength that the IPL machine uses for doing its job. Because more light is available at the desired wavelength, the overall energy delivered can be reduced, and consequently, the machine is safer. This safety factor is the primary reason we decided to purchase the Harmony to treat our patients.
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What are the alternatives to photodynamic therapy ?
There are several alternatives to PDT.
For actinic keratosis, liquid nitrogen treatments are effective and inexpensive, but they frequently leave hypopigmented scars.
Efudex cream can be applied daily for one month. It is effective, but causes prolonged inflammation of the treated lesions. Most people who have had both treatments prefer PDT.
Acne can be treated with retinoids, hormones, and Accutane.
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What is your cancellation policy?
We require 48 hours notice for cancellation of your consultation or treatment, in order to fill the appointment time. If sufficient notice is not given, the full value of the treatment to be done may be charged (minimum charge $80). If you have purchased a package, and you miss an appointment without giving sufficient notice, then that treatment is deemed to have been given, and you will receive one less treatment than you paid for.
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