Láser y terapia fotodinámica en el tratamiento del acné

Abstract

INTRODUCTION: The increasing number of failures, adverse effects and contraindications of the classic treatments has emphasized the need to develop new therapeutic options for the treatment of acne. Over the past decade, the need for an alternative treatment has led to the investigation of light sources, lasers and photodynamic therapy ( PDT ) as a novel therapy of acne. PDT and light sources can be considered as an additional tool for single or adjuvant treatment in patients presenting a relapse, or in whom other therapeutic options are not possible. The exact mechanism of PDT in acne vulgaris is not known, but 4 .pathways of action are postulated: bactericidal, damage of the sebaceous gland, decrease of the follicular obstruction and immunological response (93). The innovation of our study was to assess the efficiency and tolerance in the treatment of acne of PDT with methyl-aminolevulinate (MAL) and pulsed dye laser( PDL ). OBJECTIVES: 1.-To assess the clinical response, degree of satisfaction and tolerability of PDT with MAL and pulsed dye laser long pulse ( PDL LP ) for treatment of acne vulgaris. 2.- To evaluate the adverse effects provoked by the technique: edema, erythema, purpura, alteration of the pigmentation, blisters, exfoliation, scarring and degree of pain during treatment. 3.- To compare the effectiveness and tolerance, in acne treatment of the isolated use of the PDL LP versus PDT . MATERIALS AND METHODS: During a 20 month period between 2006 and 2007, 50 acne patients were studied. The study protocol consisted of 4-6 sessions at monthly intervals. Metvix® ( MAL ) was applied with an incubation period of 1 hour and subsequently PDL LP to 9 J/cm2, 6 msg and 7 mm spot was applied as the source of light. The statistical analysis was performed with Software SPSS 13.0 for Windows. In all the comparisons of the analysis estimations significant differences were considered to be p <0.05. A test of normality (Shapiro-Wilk) revealed that the variables were not normally distributed, and consequently the non-parametric Wilcoxon’s test was used for two matched pairs for comparing the results. CONCLUSIONS: In the present study we describe our experience in the use of laser and PDT for the treatment of acne. This work was developed to compare the utilization of alternative or adjuvant new technologies with conventional therapy. Alhough antibiotics and retinoids are the gold standard of the treatment for acne, it is necessary to develop new alternatives not only for treatment of patients with multiple contraindications, but for those that have been resistant to several therapies. In the last decade, a large number of studies have described the use of PDT in new dermatological indications, such as acne. Our study involves the development of the technique in a wide number of patients and during a long period of follow-up. Most of the studies reported used aminolevulinic acid (ALA) as photosensitizer where as in this study MAL was used. As there are very few assays using laser in PDT the novel use of PDL was selected. As a result of our study the following conclusions were obtained: 1. PDT with MAL and PDL LP , achieved a favorable clinical response in treating acne, with good tolerance of the technique and patient satisfaction with the results obtained. 2. PDT of acne can be considered a safe technique because of the virtual absence of side effects. The onset of pain during treatment was well tolerated and no patient abandoned the study . 3. When comparing the use of PDL versus PDT for the treatment of acne, it was found that PDT achieved a larger reduction in total acne lesions, mainly those of an inflammatory nature.