Topical 5-Aminolevulinic Acid Photodynamic Therapy for the Treatment of Verruca Vulgaris: Comparison of Red and Green Light-Emitting Diode Array
Verruca vulgaris or warts are benign skin papillomas caused by the human papilloma virus
(HPV). They are very common and can affect many different sites including the face, hands,
feet and genitalia. Although the present therapeutic approaches are more or less effective
in eradicating the lesions, scars and relapses are very common. Furthermore, at times the
anatomical location and depth of lesions often make the treatment difficult, time-consuming
and painful. Therefore, it is necessary to develop new modalities for wart treatment.
Photodynamic therapy (PDT) has been developed as a promising new cancer treatment modality,
which involves the uptakes of a photosensitizer by tumor cells, followed by the activation
of photosensitizer with approximate wavelength of light. The endogenous conversion of
5-aminolevulinic acid (ALA) to protoporphyrin IX (PpIX) has broadened the use of PDT. The
mechanisms of the PDT-induced cytotoxic effect relate to singlet oxygen and other reactive
oxygen intermediates generated by PDT, which give rise to cellular stress and cause cell
death. Previously, using the homemade LED light source, we have shown that topical ALA-PDT
is effective for the treatment of warts. However, the excruciating pain induced by ALA and
red LED could be due to deeper penetration of the ALA formulation or the deeper penetration
of red light. Thus the pain might be related to the injured nerve fibers underlying the
skin. This study is to provide evidence of these two green or red LED efficacy in removing
the warts and also their side-effect of pain.
Allocation: Random Sample, Observational Model: Natural History, Time Perspective: Longitudinal, Time Perspective: Prospective
Pan-Chyr Yang, Ph.D.
National Taiwan University Hospital
Taiwan: Department of Health