Photodynamic Light Treatment (PDT)
Photodynamic therapy (PDT) is a medical treatment that utilizes a photosensitizing molecule (frequently a drug that becomes activated by light exposure) and a light source to activate the applied drug. Very thin superficial skin cancers called actinic keratoses and certain other types of cancer cells can be eliminated this way. Acne can also be treated as well. The procedure is easily performed here at Harris Dermatology.
PDT essentially has three steps. First, a light-sensitizing liquid, cream, or intravenous drug (photosensitizer) is applied or administered. Occasionally, a photosensitizing molecule that is already part of the body can be activated. Second, there is an incubation period of minutes to days. Finally, the target tissue is then exposed to a specific wavelength of light that then activates the photosensitizing medication.
What Happens after Photodynamic Therapy?
Photodynamic therapy involves two steps. To begin your treatment, you'll come into the office for an application of a topical medication such as Levulan. After a designated period, you'll come back for your light therapy treatment. After this second phase of treatment during which light is applied to the skin, the topical medication remains active for two days. The medication is photosensitive, meaning that it activates when exposed to sunlight. For this reason, your dermatologist may advise you to avoid outdoor activities for at least 48 hours after your light therapy session. You can go outdoors, of course, but should wear sunscreen and protective clothing such as a hat or long-sleeved shirt.
What is the Aftercare Following Photodynamic Therapy?
In addition to avoiding direct exposure to sunlight, your aftercare instructions may include the following:
- Clean your skin using Cetaphil or another gentle cleanser.
- Use zinc or titanium sunscreen with SPF 30 or higher.
- Have 1 percent Hydrocortisone cream on hand to apply if irritation occurs.
If questions arise during your recovery from photodynamic therapy, please don't hesitate to call the office. We're here to assist you in your healing!
How Do I Prepare for My Photodynamic Therapy Treatment?
You may need to take a couple of precautions before your appointment. During your consultation, it is important to be up-front about all medications and supplements you take, if asked, as well as your medical history and lifestyle habits. If you have a history of cold sores, we may prescribe an antiviral medication for you to begin taking at least one week before your appointment. On the day of your treatment, wash your face but do not apply any products. No serums or moisturizers and no sunscreen. You may be in the office for some time to receive your treatment, so it's beneficial to bring some form of entertainment, such as a book, headphones and a phone or iPad, or other diversions.
How Does Photodynamic Therapy Help Acne?
Photodynamic therapy puts light to work in a very specific way. The photosensitizer medication that is applied to your skin causes certain types of cells to produce porphyrins. These are light-absorbing molecules that enable us to target abnormal cells. In the treatment of acne, the photosensitizing medication is activated with light. This may be red light, blue light, or intense pulsed light. Your doctor will discuss the details of your procedure during your consultation. When activated by light, the medication destroys the bacteria and cells that are contributing to acne. Additionally, PDT decreases the activity of the sebaceous glands that produce oil in the skin.
How Many Photodynamic Therapy Treatments Do I Need?
The number of treatments that you need will depend on the condition we're addressing and possibly its severity. Some conditions, such as small basal cell carcinomas, may require two PDT treatments. If you're using photodynamic therapy treatments for acne, we may set you up with a regular maintenance schedule to keep your skin healthy and clear.