Blue and Red Light Photodynamic Therapy (PDT)
Treating Actinic Keratosis and Precancerous Lesions
At Utah Valley Dermatology, we offer Photodynamic Therapy (PDT) as a highly effective, non-invasive treatment for actinic keratosis (AK) and other precancerous skin lesions. PDT uses a photosensitizing medication combined with light to target and destroy abnormal cells. Depending on the depth and severity of the lesion, either blue light or red light is used during the procedure. Here’s what you need to know about how these therapies work, the medications involved, possible side effects, and what to expect during treatment.
How Does PDT Work?
Blue Light PDT
- Wavelength: Blue light operates at shorter wavelengths (~400–450 nm), making it ideal for treating superficial lesions.
- Applications: It is most commonly used for actinic keratosis on areas like the face, scalp, arms, and neck.
- Mechanism: After applying a photosensitizer like 5-aminolevulinic acid (ALA), blue light activates the medication. This interaction produces reactive oxygen species (ROS) that destroy abnormal cells on the surface of the skin.
Red Light PDT
- Wavelength: Red light has longer wavelengths (~630–690 nm), allowing it to penetrate deeper into the skin.
- Applications: Red light is used for thicker lesions or more advanced precancerous conditions that require deeper penetration.
- Mechanism: Similar to blue light, red light activates the photosensitizer to produce ROS. However, red light can reach deeper layers of skin, making it more effective for thicker AKs or lesions that are resistant to blue light therapy.
What Should I Expect During Treatment?
- Preparation: The treatment area will be cleansed before applying the photosensitizer (ALA). The medication is left on the skin for about 60–90 minutes to allow it to absorb into abnormal cells.
- Light Exposure:
- For blue light therapy, patients are exposed to blue light for approximately 16 minutes.
- For red light therapy, exposure time may vary but generally lasts longer due to deeper penetration requirements.
- Post-Treatment Care:
- After treatment, your skin may appear red and feel similar to a sunburn.
- It’s crucial to avoid direct sunlight for at least 30 hours after treatment because your skin will be highly sensitive due to residual photosensitizer.
What Are The Side Effects?
While PDT is generally well-tolerated, there are some common side effects:
- Redness and swelling: The treated area may appear red and swollen for several days post-treatment.
- Pain or discomfort during treatment: Patients undergoing red light therapy may experience more discomfort than those receiving blue light due to its deeper penetration.
- Photosensitivity: After treatment, your skin will be extremely sensitive to sunlight for up to 48 hours. It’s essential to avoid sun exposure and use protective clothing or sunscreen during this period.
- Crusting or peeling: In some cases, treated areas may develop crusts or peel as part of the healing process.
Most side effects resolve within a week as your skin heals.
What Is It Like?
Patients often describe PDT as a relatively simple procedure with minimal downtime compared to other treatments like cryotherapy or surgical excision. Here’s what you can expect:
- During treatment, you may feel mild tingling or burning sensations as the light activates the photosensitizer.
- Afterward, your skin will be red and tender—similar to a sunburn—but this usually subsides within a few days.
- Most patients are able to return to normal activities within 24–48 hours but should avoid direct sunlight for at least 30 hours following treatment.
At Utah Valley Dermatology, we ensure that every patient receives personalized care tailored to their specific needs. Whether you’re undergoing blue or red light therapy, our team will guide you through each step of the process and provide detailed post-treatment care instructions.
TREATMENT OVERVIEW
TYPE:
• Skin cancer
BENEFITS:
- Targets and destroys most pre-cancer
- Treats sun damage
RESULTS:
- Reduced risk of future skin cancers
