Photodynamic therapy
Photodynamic therapy (PDT) is a minimally invasive dermatological treatment that uses a combination of a photosensitizing agent and a specific light source to selectively destroy abnormal or diseased skin cells. It is FDA-approved for actinic keratosis (AK) and widely used for superficial basal cell carcinoma (sBCC) and moderate to severe acne, offering both therapeutic and cosmetic benefits.
How PDT Works
PDT involves three key steps:
- Application of a photosensitizing agent (e.g., 5-aminolevulinic acid or methyl aminolevulinate) to the affected skin.
- Incubation period (usually 1–3 hours) to allow the agent to be absorbed by abnormal cells.
- Exposure to a specific light source (blue or red light) activates the agent and produces reactive oxygen species that destroy targeted cells.
Indications and Benefits
1. Actinic Keratosis (AK)
AKs are precancerous lesions caused by sun damage. PDT is highly effective in clearing multiple lesions in a single session, especially on the face and scalp. It offers excellent cosmetic outcomes with minimal scarring.
2. Superficial Basal Cell Carcinoma (sBCC)
PDT is a non-surgical option for low-risk sBCC, particularly in cosmetically sensitive areas. It provides good clearance rates and superior aesthetic results compared to excision or cryotherapy.
3. Acne Vulgaris
PDT reduces acne by targeting Cutibacterium acnes bacteria and shrinking sebaceous glands. It also decreases inflammation and improves skin texture, making it a valuable option for patients unresponsive to conventional treatments.
Advantages of PDT
- Non-invasive and typically performed in-office
- Minimal downtime (redness and peeling for a few days)
- Excellent cosmetic results
- Can treat large or multiple areas simultaneously
- Low systemic side effects
What to Expect
Patients should avoid sun exposure for 24–48 hours post-treatment due to temporary photosensitivity. Mild discomfort, redness, and peeling are common but usually resolve within a week. Multiple sessions may be needed for optimal results, especially in acne or extensive lesions