Psoriasis response to the pulsed dye laser

Background and Objective In psoriasis the blood vessels are enlarged and dilated. These vessels, the psoriatic microvasculature, have been implicated as participating in the pathogenesis of psoriasis. The purpose of this preliminary study was to use the flashlamp‐pumped pulsed dye laser, which selectively damages dermal vessels, to treat psoriatic plaques and to evaluate the role of the vasculature in the therapeutic response. Materials and Methods Ten patients with psoriasis were treated with the pulsed dye laser on single, stable psoriasis plaques. Treatments varied between one and three times, and the lesional response was graded using a scale for erythema, scaling, and infiltration. Results Six of 10 patients experienced a beneficial clinical effect after therapy. The psoriasis severity scale in these patients was reduced to 2.2 ± 1.3 compared with a 7.2 ± 1.7 grade for control areas. The plaques readily developed crusting with therapy, with one leg lesion healing with atrophy. Histopathology in three patients immediately after therapy showed no epidermal damage. One week after laser therapy, the necrotic former epidermis was apparent in superficial crusting. Epidermal thinning and regeneration was seen without any signs of psoriasis. Conclusions Pulsed dye laser therapy may improve plaque psoriasis. This improvement may be related to the role the microvasculature plays in psoriasis. © 1996 Wiley‐Liss, Inc.