The flashlamp-pumped dye laser and dermabrasion in psoriasis--further studies on the reversed Köbner phenomenon.

Eleven patients with chronic plaque psoriasis were treated with the flashlamp-pumped pulsed dye laser and 6 of the same patients were at the same time treated by dermabrasion. Complete remissions were observed in 3 patients following laser-treatment and in 5 of 6 after dermabrasion. The observation periods were from 4 to 9 months. Our data suggest that the mechanism of the reversed Köbner phenomenon, which is thought to be responsible for the results of dermabrasion, is partly due to destruction of the dermal papillary vasculature. Partial responses were seen in 6 laser-treated and in one patient treated by dermabrasion. Two patients showed no response to laser treatment. These clinically unsatisfactory results can be explained by the great variety in thickness of plaques and in variability of penetration of the laser light. Measurements of absorption and scattering properties of plaques scheduled for laser treatment could probably allow improvements in the technique by optimizing laser beam diameter and pulse duration as well as wavelength and energy levels. The use of the dye laser is far less traumatic to the patient than dermabrasion.