Itching in patients suffering from psoriasis.

Some psoriatic patients suffer from intensive itching, however, literature data on its prevalence and especially on clinical manifestation are very limited. This study was undertaken to evaluate the frequency and clinical characteristics of itching in patients with psoriasis and to correlate the presence and intensity of pruritus with clinical severity of psoriasis. One hundred psoriatic individuals (psoriasis vulgaris in 77% and arthropatic psoriasis in 23%) were included in the study. The severity of psoriasis was assessed according to PASI score. Itching was evaluated using two methods: visual analog scale (VAS) and a specially designed questionnaire method. Itching was found in 80% of psoriatic patients. The severity of psoriasis in pruritic patients was significantly (p<0.004) higher as compared to non-pruritic subjects. Significant correlations were found between PASI scores and intensity of itching, as assessed by both scales: VAS and the questionnaire method (r=0.29, p<0.01 for both analyses). The presence and intensity of itching did not depend on age and gender of patients, type of psoriasis, duration of disease, and last outbreak of psoriasis. Generalized itching was reported by 28.7% of pruritic patients. The most common sites of itching were lower limbs (50%), trunk (48.7%), upper limbs (48.7%) and scalp (35%). Face appeared to be the least commonly affected skin area by itching (only 1.2%). We conclude that itching is a common symptom in patients with psoriasis, and its intensity correlates with clinical severity of the disease.

Plasma neuropeptides and perception of pruritus in psoriasis.

The aim of this study was to evaluate the influence of selected neuropeptides on itching in psoriatic individuals. Fifty-nine patients (43 pruritic and 16 non-pruritic) with psoriasis were included in the study. The severity of psoriasis, measured using the Psoriasis Area and Severity Index scale, ranged between 2 and 43.7 points. The intensity of pruritus was evaluated using a Visual Analogue Scale. The plasma levels of substance P, vasoactive intestinal peptide, calcitonin gene-related peptide and neuropeptide Y were measured radioimmunologically. The plasma level of neuropeptide Y was significantly decreased in patients with pruritus compared with those without pruritus (21.6 +/- 39.6 pg/ml and 144.3 +/- 385.7 pg/ml, respectively; p=0.03). Levels of other neuropeptides did not differ significantly between pruritic and non-pruritic patients; however, a tendency to lower plasma levels of substance P and vasoactive intestinal peptide in patients with itching was noted. Moreover, a significant negative correlation was observed between pruritus severity and levels of substance P (r = -0.36; p=0.02), as well as between pruritus severity and plasma levels of vasoactive intestinal peptide (r = -0.34; p=0.03). The imbalance of neuropeptide activity in the sera of pruritic subjects may suggest a role for neuropeptides in perception of itching in psoriatic individuals.

Plasma concentration of selected neuropeptides in patients suffering from psoriasis.

UNLABELLED: The aim of this study was to evaluate plasma levels of substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) during psoriasis course. METHODS: Seventy-three patients with psoriasis and 32 healthy volunteers were included. Detailed demographic and disease anamnesis was obtained from every patient. The disease severity was assessed using the Psoriasis Area and Severity Index score. Plasma levels of SP, CGRP, VIP and NPY were measured radioimmunologically. RESULTS: Plasma levels of SP and NPY did not significantly differ between patients with psoriasis and controls (median SP: 52.8 and 57.9 pg/ml, respectively; P = 0.32; median NPY: 8.5 and 8.2 pg/ml, respectively; P = 0.67). CGRP plasma concentration was significantly elevated in psoriatic individuals both before (median 43.1 pg/ml) and after treatment (median 45.4 pg/ml), in comparison with healthy donors (median 13.5 pg/ml; P < 0.01 and P = 0.03, respectively). Treatment did not significantly influence plasma CGRP levels (P = 0.3). Median VIP plasma concentration in psoriatics before treatment was significantly higher compared with healthy controls (medians 66.9 and 60.1 pg/ml, respectively; P = 0.04), but the therapy resulted in significant decrease in VIP plasma level (median 19.0 pg/ml; P < 0.001). In psoriatic patients significant correlations were noted between NPY and VIP (R = 0.34; P < 0.01), and VIP and CGRP plasma levels, both before (R = 0.28; P = 0.03) and after the treatment (R = 0.44; P < 0.01). CONCLUSIONS: Based on our results and previous literature data it could be suggested that neuropeptides may be involved in the development of psoriatic lesions.