Cutaneous Blood Flow in Psoriasis

Abstract

The disappearance rate of 133Xe was studied in 20 patients with psoriasis vulgaris, using an epicutaneous labeling technique in involved skin lesions or normal-appearing skin of the proximal extensor site of the forearm. Control experiments were performed in 10 normal subjects. Calculations of the cutaneous blood flow (CBF) in psoriatic skin lesions were performed using a tissue-to-blood partition coefficient for 133Xe, lambda c,pso, of 1.2 ml/100 g/min. lambda c,pso was estimated after the relative content of water, lipids, and proteins had been analyzed in psoriatic skin biopsies of 6 patients with untreated psoriasis. The mean relative content of water was markedly reduced to 23.5 +/- 1.5% (SEM), and lipids and proteins were markedly increased to 2.5 +/- 0.7% and 74.0 +/- 2.2, respectively, compared to previously published data for normal skin (water 72.5%, lipids 1%, proteins 26.5%). Mean CBF in untreated psoriatic skin was 63.5 +/- 9.0 ml/100 g/min. This was significantly higher than the mean CBF in 10 normal subjects, 6.3 +/- 0.5 ml/100 g/min (p much less than 0.0001). Mean CBF in normal-appearing skin in patients with psoriasis was 11.0 +/- 1.3 ml/100 g/min. This was significantly higher than CBF in normal subjects (p less than 0.0002).

Videocapillaroscopic Findings in the Microcirculation of the Psoriatic Plaque

“…In the lesional skin, flow has been shown to be 10 times greater than in normal skin when measured by 133 Xe washout [6]or 13 times greater when measured using a laser Doppler flowmeter [7]. This means that in plaque skin either there are more vessels or there is chronic, structural widening of the existing vessels [7].…”

Global Gene Expression Analysis Reveals Evidence for Decreased Lipid Biosynthesis and Increased Innate Immunity in Uninvolved Psoriatic Skin

“…These were characterized by changes in phospholipid composition and levels and distribution of several hydrolytic enzymes and dehydrogenases (Braun-Falco, 1971; Wilkinson, 1971). Furthermore, increased biosynthesis of arachidonic acid metabolites (Ziboh et al , 1984) and increased blood flow has been noted in PN skin (Klemp and Staberg, 1983) but the etiology of these changes is unknown.…”

Mathematical Modelling of Nitric Oxide Regulation of Rete Peg Formation in Psoriasis

“…We base the value of g on estimates that blood #ow in the dermal papillae of psoriatic plaques is between two and "ve times greater than in normal skin (Klemp & Staberg, 1983;Krogstad et al, 1995). Assuming Poiseuille #ow in the vessels, this implies an increase in blood vessel area by factor of between 1.4 and 2.2 ((2}(5).…”