Photodynamic therapy is an in-office procedure most commonly used for the treatment of pre-cancerous skin lesions (actinic keratoses). These are rough, scaly patches, caused by excessive exposure to the sun, that can sometimes progress to squamous cell skin cancer if left untreated. It is estimated that approximately 40% of squamous cell carcinomas, which are the second leading cause of skin cancer deaths in the US, begin as actinic keratoses. The American Cancer Society, the Skin Cancer Foundation, and the American Academy of Dermatology all recommend that people with actinic keratoses seek treatment for them directly.
When photodynamic therapy is performed, a topical solution of Levulan Kerastick (20% aminolevulinic acid) is applied in the office one hour prior to the procedure. This is painless. The area to be treated is then exposed to a special blue light for just under 17 minutes. A tingling or mild stinging sensation may be experienced. This sensation is eased by cool air blowing over the skin. Protective eyewear is worn while the skin is exposed to the light. After the procedure, you may experience mild puffiness and stinging, comparable to a mild sunburn. Post treatment, bright fluorescent lights and sunlight must be strictly avoided for 48 hours.
This is a highly effective treatment for actinic keratoses, and most patients are impressed at how smooth their skin looks and feels after several days. Although not its primary intent, photodynamic therapy also produces some tightening of the skin. This modality can also be used to improve sebaceous hyperplasia, a condition in which sebaceous glands, which normally reside in the deeper layers of the skin, appear on the surface as yellowish-white bumps. In addition, photodynamic therapy has a limited role in the treatment of recalcitrant acne.