Histamine, Substance P and Calcitonin Gene-Related Peptide Plasma Concentration and Pruritus in Patients Suffering from Psoriasis

Abstract

Background: Many patients with psoriasis suffer from itch. The pathogenesis of psoriatic itch still remains unknown. Objective: To evaluate the relationships between plasma levels of histamine, substance P (SP) and calcitonin gene-related peptide (CGRP) and the presence as well as intensity of itching among psoriatic patients. Patients and Methods: 59 psoriatic individuals (43 pruritic and 16 non-pruritic) and 32 healthy controls were included in the study. Itching was evaluated by a visual analog scale (VAS) and a specially designed questionnaire. Plasma concentrations of histamine, SP and CGRP were measured by RIA (radioimmunoassay) method. Results: The mean plasma concentration of histamine in psoriatic patients was not significantly different from that found in controls. No significant differences were found between plasma levels of histamine in the groups of psoriatic pruritic patients, non-pruritic psoriatics and controls. Also, there was no significant difference in SP plasma concentration between psoriatic individuals and controls or between pruritic, non-pruritic and healthy people. No relationships between the substances studied (histamine, SP) and intensity of pruritus could be revealed. The mean CGRP plasma level was markedly increased in patients suffering from psoriasis as compared to controls (p < 0.01). The mean CGRP concentration in the plasma of pruritic psoriatic patients was significantly higher than in controls (p < 0.01). This was not observed when comparing non-pruritic to healthy subjects. The mean concentration of CGRP in the plasma of pruritic patients was also higher than in that of non-pruritic ones, but this difference did not reach statistical significance. A significant correlation was found between itching intensity and CGRP plasma concentration in male subjects and in those patients who had been suffering from psoriasis for 5–20 years. There were, however, no correlations between CGRP level and itching intensity in the whole group of 43 psoriatic patients with pruritus. Conclusion: Circulatory CGRP could be an important factor in the pathogenesis of psoriatic pruritus, but this still needs further investigation.

A randomized controlled trial on the anti-inflammatory effects of curcumin in patients with chronic sulphur mustard-induced cutaneous complications

“…CGRP is expressed by keratinocytes and its levels are increased in human chronic pain or chronic pruritus conditions such as atopic dermatitis and pruritus. 31,32 CGRP also promotes inflammation through up-regulation of IL-1 and IL-8 and endothelial-leukocyte adhesion molecule 1, chemotaxis of neutrophils and translocation of P-selectin. 33,34 Regarding the contribution of this mediator to the perception of both pain and pruritus, its reduction by curcumin could represent a plausible mechanism for the promising results observed in the present study.…”

Plasma concentration of selected neuropeptides in patients suffering from psoriasis

“…Both neuropeptides were found to be overexpressed in lesional psoriatic skin (17,(20)(21)(22). CGRP was also supposed to mediate in pruritus perception in psoriatic individuals (37,38). Moreover, in active psoriatic lesions, CGRP also was found to be produced by Langerhans cells (22).…”

Plasma Neuropeptides and Perception of Pruritus in Psoriasis

“…All patients underwent careful dermatological examination: the severity of psoriasis was assessed according to the Psoriasis Area and Severity Index (PASI) (20) and pruritus intensity according to a standard Visual Analogue Scale (VAS) (II). Although the VAS is a highly subjective scale, it has been widely accepted for pruritus intensity assessment (18,21) and was also used by our group in previous studies on pruritus (11,13,14). Both disease severity and pruritus intensity were measured on the same day as blood sampling.…”

“…The severity of pruritus correlates only poorly,, if at all, with disease severity (10,11). Histamine, one ofthe major mediators of pruritus, seems not to be involved in pruritus development in psoriasis, as there was no correlation between pruritus intensity and histamine plasma level and no difference in histamine plasma levels between pruritic and non-pruritic patients with psoriasis (13). Moreover, a treatment with anti-histaminics rarely brings relief, and this seems to be connected with its sedative effect rather than with anti-histaminic properties (11).…”