Department of Dermatology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
Br J Dermatol. 2013 Feb;168(2):253-6. doi: 10.1111/bjd.12043.
Patients with central centrifugal cicatricial alopecia (CCCA) often suffer from varying degrees of itch, pain and burning sensations. However, the neural component of these skin sensations has not been assessed.
To conduct a comprehensive analysis of C nerve fibre function relating to itch and pain perception in patients with CCCA using thermosensory testing and experimental itch models.
Fifteen healthy African-American women and 16 African-American female patients with CCCA participated in the study and underwent quantitative computerized thermosensory testing to assess warmth and heat pain thresholds. Itch was induced using histamine iontophoresis and application of cowhage spicules, and the intensity of each itch was assessed. The association between itch intensity and CCCA severity score was examined.
A positive correlation between CCCA severity score and peak itch ratings of cowhage on the lesional scalp (crown) was observed (P = 0·023, r = 0·562). Notably, the histamine peak itch rating was not found to have a significant correlation with CCCA severity score (P = 0·913). The crown also had significantly higher warmth and pain thresholds than the occiput in both healthy subjects and patients with CCCA.
Our results suggest a putative role for the protease-activated receptor (PAR)-2, which is activated by cowhage, in the pathogenesis of CCCA. Future studies should examine PAR-2-directed therapeutics for patients with CCCA. Examining for itch and other dysaesthesias in patients with CCCA is of vital importance to dermatologists in assessing disease severity.
患有中心离心性瘢痕性脱发（CCCA）的患者常伴有不同程度的瘙痒、疼痛和烧灼感。然而，这些皮肤感觉的神经成分尚未得到评估。
使用温度感觉测试和实验性瘙痒模型，全面分析与 CCCA 患者瘙痒和疼痛感知相关的 C 神经纤维功能。
15 名健康的非裔美国女性和 16 名非裔美国女性 CCCA 患者参与了这项研究，并接受了定量计算机温度感觉测试，以评估温暖和热痛阈值。使用组织胺离子电渗法和牛痘刺毛的应用来诱发瘙痒，并评估每种瘙痒的强度。检查瘙痒强度与 CCCA 严重程度评分之间的关联。
观察到 CCCA 严重程度评分与病变头皮（头顶）上牛痘的峰值瘙痒评分之间存在正相关（P=0.023，r=0.562）。值得注意的是，组织胺的峰值瘙痒评分与 CCCA 严重程度评分之间没有显著相关性（P=0.913）。与 CCCA 患者的枕部相比，头顶的温暖和疼痛阈值也明显更高。
我们的结果表明，蛋白酶激活受体（PAR）-2 在 CCCA 的发病机制中可能发挥作用，该受体被牛痘激活。未来的研究应检查针对 CCCA 患者的 PAR-2 定向治疗。检查 CCCA 患者的瘙痒和其他感觉异常对于皮肤科医生评估疾病严重程度至关重要。
