Psoriasis and the arachidonic acid cascade

Arachidonic acid (5,8,11,14-eicosatetraenoic acid, C20:4, n-6) is released From the cell membrane by the action of phospholipases on membrane phosphol ipids. Metabolites of arachidonic acid, which are generically termed eicosa noids, including prostaglandins, thromboxane, leukotrienes and hydroxyeicos atetraenoic acids, have been implicated as mediators or modulators of a num ber of physiological functions and pathological conditions in both normal a nd diseased human skin. Particularly, eicosanoids have been suspected to pl ay an important role in the pathogenesis of psoriasis, because a number of phenomena observed in psoriasis can be explained, at least in part, by the action of eicosanoids. This review will focus on recent progress regarding the significance of eicosanoids in the pathogenesis of psoriasis. Recent de velopments in the molecular biology in the eicosanoids have renewed interes t in the role of eicosanoids in psoriasis. New understanding of the etiolog y of psoriasis and advances in its treatment due to recent progress in eico sanoid biology will also be presented. (C) 1999 Elsevier Science Ireland Lt d. All rights reserved.