Comparison of the cutaneous thermal signatures over twenty-four hours with a picosecond alexandrite laser using a flat or fractional optic

INTRODUCTION: This study explored immediate heat signatures with different passing techniques and the delayed thermal data points with the picosecond Alexandrite laser with the 6mm at and fractional optic during and after treatment. We sought to clarify the immediate effects of heating and understand the thermal and short term clinical difference when using these optics. RESULTS: There were no immediate differences or a signi cant temperature rise with different passing techniques using the at or the fractional optic. However, after treatments a signi cant temperature elevation over 24 hours with manageable erythema was noted with the fractional optic. Only faint redness was appreciated with the at optic. CONCLUSION: The different passing methods with these optics did not result in a significant thermal change. However, the fractional optic produces a localized area of epidermal necrosis which results in a significant clinical and a delayed thermal effect. With multiple treatments over time, collagen, elastic tissue, and mucin is produced resulting in improvement of acne scars and photo-damaged skin. This process suggests that a well-placed epidermal injury can stimulate an inflammatory cascade with dermal remodeling.