Acta dermato-venereologica
-
Acta Derm. Venereol. · Sep 2013
German version of ItchyQoL: validation and initial clinical findings.
Pruritus is a major symptom of numerous skin and systemic diseases and causes a substantial burden on patients' quality of life (QoL). We report here the validation of the German version (GerItchyQoL) of the first pruritus-specific QoL instrument ItchyQoL. GerItchyQoL was created from the original version following standard protocols. ⋯ Changes in GerItchyQoL scores correlated with changes in itch severity (VAS), suggesting responsiveness of the German tool. This study provides preliminary evidence of validity, reliability and responsiveness of GerItchyQoL and also shows a high impact of chronic pruritus on QoL. Further translations of ItchyQoL into additional languages will enable large-scale international, multilingual trials.
-
Acta Derm. Venereol. · Jul 2013
Comparative StudyMechano-insensitive nociceptors are sufficient to induce histamine-induced itch.
The nerve fibres underlying histamine-induced itch have not been fully elucidated. We blocked the lateral femoral cutaneous nerve and mapped the skin area unresponsive to mechanical stimulation, but still sensitive to electrically induced pain. Nerve block induced significantly larger anaesthetic areas to mechanical (100 mN pin-prick, 402 ± 61 cm²; brush, 393 ± 63 cm²) and heat pain stimuli (401 ± 53 cm²) compared with electrical stimulation (352 ± 62 cm², p < 0.05), whereas the anaesthetic area tested with 260 mN (374 ± 57 cm²) did not differ significantly. ⋯ In these areas iontophoresis of histamine provoked itching in 8/9 subjects with a mean maximum of 4.6 ± 1 (on an 11-point rating scale). Histamine-induced itch can thus be perceived at skin sites where input from mechano-sensitive polymodal nociceptors is blocked. In conclusion, input from mechano-insensitive nociceptors is sufficient to generate histamine-induced itch.