Perianal Crohn's disease (pCD) is a complex manifestation of Crohn's disease. Classifying this patient cohort for both clinical purposes and for inclusion into research trials is challenging but crucial in order to improve outcomes. This review provides an overview of historical classifications of both fistulising and non-fistulising pCD, including the Park's, Cardiff-Hughes and American Gastroenterological Association (AGA) classifications, as well as recent advances including the Treatment Optimisation and CLASSification of perianal Crohn's disease (TOpClass) classification of fistulising pCD. Secondly, this article provides a scoping review of recent trials in pCD and describes how the cohorts in these trials relate to the TOpClass classification. Of the 19 studies relating to pCD that were identified, four could be confidently classified as class 2a. Seven could be classified as class 2a or 2b, but it was not possible to subdivide further, and seven to class 2a, 2b or 2c, but it was not possible to subdivide further. One study population was classified as class 2a or 2c. In eight studies, it was not specified whether patients with a defunctioning stoma were included or excluded. This review demonstrates the heterogeneous nature of some patient cohorts in previous clinical trials, and how the TOpClass classification may be used to group patients more accurately for clinical use and inclusion in research trials.

Keywords: Classification; Fistula; Perianal Crohn’s disease; Phenotype.

© 2025. The Author(s).

会阴部克罗恩病（pCD）是克罗恩病的一种复杂表现形式。为了临床应用和纳入研究试验而对这种患者群体进行分类既具有挑战性又至关重要，以便改善预后。本文综述了瘘管型和非瘘管型pCD的历史分类方法，包括Park分类、Cardiff-Hughes分类和美国胃肠病学会（AGA）分类，以及最近的进展，如治疗优化与会阴部克罗恩病分类（TOpClass）分类法中的瘘管型pCD。其次，本文提供了关于近期pCD试验的一次范围性回顾，并描述了这些试验中患者群体如何与TOpClass分类相关联。在确定的19项有关pCD的研究中，有四项可以被自信地归类为2a类。七项研究可以被归类为2a或2b类，但无法进一步细分；另外七项可归类为2a、2b或2c类，也无法进一步细分。一项研究群体被分类为2a或2c类。在八项研究中，未说明是否包括了造口患者或排除了这些患者。本文展示了之前临床试验中的某些患者群体的异质性，并阐述了TOpClass分类如何用于更准确地将患者分组以供临床使用和纳入研究。

关键词：分类；瘘管；会阴部克罗恩病；表型。

© 2025. The Author(s).