St. John's Institute of Dermatology, Guy's Hospital, London, UK.
Exp Dermatol. 2022 Apr;31(4):586-593. doi: 10.1111/exd.14493. Epub 2021 Nov 12.
Solar urticaria is a rare, immunologically mediated photodermatosis in which activation of cutaneous mast cells is triggered by specific wavelengths of solar electromagnetic radiation. This manifests clinically as the rapid development of cutaneous itch, erythema and wheal formation after several minutes of sun exposure. Disease mechanisms in solar urticaria remain incompletely elucidated and there have been few recent investigations of its pathobiology. Historic passive transfer experiments performed during the twentieth century provide support for a 'photoallergy' model of disease pathogenesis, wherein molecular alteration of a putative chromophore by solar electromagnetic radiation produces mast cell activation via an IgE-dependent mechanism. However, this model does not account for several observations made during passive transfer experiments nor does it explain a range of subsequent clinical and photobiological observations made in solar urticaria patients. Furthermore, increased understanding of the molecular dynamics underpinning cutaneous mast cell responses highlights the need to reformulate our understanding of solar urticaria pathogenesis in the context of this contemporary scientific landscape. In this review, we discuss the current understanding of solar urticaria pathogenesis and, by incorporating recent scientific and clinical observations, develop new hypotheses to drive future investigation into this intriguing disorder.
日光性荨麻疹是一种罕见的免疫介导性光皮病，其皮肤肥大细胞的激活是由特定波长的太阳电磁辐射触发的。这在临床上表现为暴露于阳光下几分钟后，皮肤迅速出现瘙痒、红斑和风团。日光性荨麻疹的发病机制仍不完全清楚，最近对其病理生物学的研究也很少。在 20 世纪进行的历史性被动转移实验为疾病发病机制的“光过敏”模型提供了支持，其中太阳电磁辐射对假定的发色团的分子改变通过 IgE 依赖性机制产生肥大细胞激活。然而，该模型不能解释在被动转移实验中观察到的一些现象，也不能解释在日光性荨麻疹患者中随后进行的一系列临床和光生物学观察。此外，对支持皮肤肥大细胞反应的分子动力学的深入了解，需要我们根据这一当代科学背景重新构建对日光性荨麻疹发病机制的理解。在这篇综述中，我们讨论了日光性荨麻疹发病机制的现有认识，并通过纳入最近的科学和临床观察，提出了新的假设，以推动对这一有趣疾病的进一步研究。
