Photodynamic Therapy (PDT) for Sun Damaged Skin

Everyone knows that sunburn is uncomfortable - and PREVENTABLE. The thing that most people do not consider is the damage that done by over exposure to the sun. Sun damaged skin is not a temporary condition. Although the initial pain, redness, burning, peeling, itching, etc., subsides after only a few days, the damage to those cells could result in much more serious issues requiring treatment.

Sun damage is very common but can have serious consequences. Sun exposure can lead to premature skin aging, wrinkles, age spots, freckles, and even skin cancers. The damage to the cells in the dermal tissue reduces the elasticity of the skin and makes a person appear older. Sunburns from childhood could result in all of these things. The more times you are sunburned, whether it is first or second degree, the more you are at risk of permanent damage.

Fortunately, there are treatments that can reverse some of the damage, but PREVENTION is the key to maintaining healthy skin. Using 30SPF sunscreen, wearing broad rimmed hats and long sleeves, taking frequent breaks in the shade, and staying hydrated are some of the best ways to nurture healthy skin while enjoying the great outdoors. It is also important to hydrate the skin at a topical level with moisturizing lotions and creams following sun exposure.

Dermatologists offer several treatment options for damaged skin such as chemical peels, exfoliation, laser treatments, and photodynamic treatments.

Photodynamic Therapy directs wavelengths of blue fluorescent light to activate a topical medication that has been applied to the damaged skin. It selectively kills abnormal and potentially cancerous cells. It is very effective in treating broad areas of sun damage and can be performed in the office, although depending on the severity of the damage, may involve more than one treatment. Treating an affected region of the skin is called "field therapy" and allows the practitioner to get all the small areas at once and also treat areas below the surface of the skin that cannot be seen by the naked eye.

PTD is performed in three steps.

• Application - First a liquid photosensitive agent called aminolevulinc acid (ALA) is applied to the affected area.
• Incubation - Abnormal cells in the skin biochemically convert the ALA into protoporphyrin IX, a naturally occurring substance that is extremely sensitive to light. The practitioner determines how long the incubation period should be, but the longer the wait, the stronger the effect. Depending on the severity of the damage that time can range from 90 minutes to 4-6 hours.
• Exposure - Following the incubation period, the patient sits in front of blue flourescent light for 16 minutes. During light exposure, patients feel tingling and mild burning sensations, but those subside once the light is turned off. If the burning is too intense, the patient can take short breaks, but must complete the full 16 minutes.

The protoporphyrin IX absorbs energy from the blue light and converts it into oxygen free radicals, which damage and kill the abnormal cells. Because the medication is activated only by abnormal cells, potentially cancerous cells, they are primarily the ones that are eliminated during treatment.

Aside from redness and peeling, some patients are more sensitive and have a more severe reaction, such as blisters and scabs, but those are transient also. The eyes can be irritated by the blue light so the patient wears goggles during the treatment or the practitioner may place moist gauze over their eyes.

If you suspect that you have sun damage (and you most likely do), please consult with a dermatologist for assessment. You can talk with your PCP and get a referral if that is more comfortable.