University of Brest, LIEN, Brest, France.
Department of Dermatology, University Hospital of Brest, Brest, France.
Exp Dermatol. 2019 Dec;28(12):1470-1473. doi: 10.1111/exd.13991. Epub 2019 Jul 31.
Sensitive skin is defined by the occurrence of unpleasant sensations such as tingling, burning, tautness, itching or pain. Mechanisms explaining sensitive skin are controversial, and many hypotheses have been proposed. Because sensitive skin is primarily characterized by a wide variety of neuropathic-like symptoms, it is highly likely that neurosensory dysfunction in the skin represents one of the pathological mechanisms of sensitive skin. This hypothesis does not exclude other explanations like role of keratinocyte, transient receptor potential channels, vasculature or environmental factors. Nevertheless, the role of the nervous system in the development of sensitive skin is crucial, and growing evidence supports this hypothesis. Pain and pruritus described by patients with sensitive skin correspond to neuropathic component, and its assessment shows an increase in neuropathic measures (DN-4, Douleur Neuropathique 4) compared with control. These sensations are similar to the sensations observed in small-fibre neuropathy (SFN), which is a group of disorders that affect thin nerve fibres. One study on the pathophysiology of sensitive skin demonstrated that intra-epidermal nerve fibre density, especially of peptidergic C-fibres, was lower in the sensitive skin group. A recent study showed a modification in heat-pain detection threshold in patients with sensitive skin. All these results indicate that C-fibre damage can help explain sensitive skin. Consequently, the role of the nervous system is increasingly obvious. Nevertheless, keratinocytes and other epidermal cells closely participate in sensory transduction. Therefore, the results of neurophysiological studies should be interpreted in the light of this information that the whole epidermis represents a huge polymodal nociceptor.
敏感性皮肤的定义是出现刺痛、灼热、紧绷、瘙痒或疼痛等不愉快感觉。解释敏感皮肤的机制存在争议，提出了许多假说。由于敏感皮肤主要表现为多种类神经病样症状，因此皮肤的感觉神经功能障碍极有可能是敏感皮肤的病理机制之一。这一假说并不排除角质形成细胞、瞬时受体电位通道、血管或环境因素等其他解释。然而，神经系统在敏感皮肤的发展中起着至关重要的作用，越来越多的证据支持这一假说。敏感皮肤患者描述的疼痛和瘙痒属于神经病理性成分，其评估显示神经病理性测量值（DN-4，神经病理性疼痛 4）较对照组增加。这些感觉类似于小纤维神经病（SFN）中观察到的感觉，SFN 是一组影响细神经纤维的疾病。一项关于敏感皮肤病理生理学的研究表明，敏感皮肤组表皮内神经纤维密度，特别是肽能 C 纤维，较低。最近的一项研究显示，敏感皮肤患者的热痛检测阈值发生了变化。所有这些结果表明 C 纤维损伤有助于解释敏感皮肤。因此，神经系统的作用越来越明显。然而，角质形成细胞和其他表皮细胞密切参与感觉转导。因此，神经生理学研究的结果应根据这一信息进行解释，即整个表皮代表一个巨大的多模态伤害感受器。
