Photodynamic Therapy (PDT)

Photodynamic Therapy (PDT) is a technique to selectively destroy targeted tissue with a chemical that is activated by a light source. We use Levulan Kerastick (5 aminolevulinic acid) topically applied as the photosensitizing agent. The 5 aminolevulinic acid (ALA) is absorbed by the abnormal skin such as Actinic Keratosis, sun damaged skin, abrasions, inflammation, psoriasis, freckled skin, superficial basal cell carcinoma and squamous cell carcinoma more readily than normal skin. ALA is also absorbed by the pilosebaceous gland that is associated with acne. In the skin it is converted to protoporphyrin IX (PpIX). When PpIX is activated by a blue light such as BLU-U it produces free radicals that destroy the abnormal cells and spare the normal cells.

PDT has two significant applications, Acne and precancerous actinic keratosis and early superficial skin cancers. Acne is caused by localized infections of the skin’s pilosebaceous glands. ALA is preferentially absorbed by the pilosebaceous glands and converted to PpIX. The bacteria that causes acne, Propionibacterium acnes produces its own endogenous photosensitizer, coproporphyrin. The BLU-U light will activate both the PpIX within the pilosebaceous glands and the coproporphyrin within the pathologic bacteria destroying boths the glands and the bacteria. PDT for acne may require a series of treatments and patients should expect long-term clearance of the acne. This is not a permanent cure for acne and patients may require repeated treatments.

PDT is also excellent for severely sun damaged skin with multiple precancerous and early cancerous skin lesions that are just too numerous to individually remove. PDT treatment is effective and replaces the need for the inconveniently long treatment cycle of Efudex.