Iliopsoas abscess in crohn’s disease: systematic review of case reports and case series

Abstract

Transmural inflammation is a hallmark of Crohn’s disease (CD), a chronic inflammatory bowel disease that exposes patients to serious consequences such as fistulas and abscesses. Iliopsoas abscess (IPA) is an uncommon but potentially fatal penetrating (extra-luminal) complication of CD that frequently arises from the direct extension of transmural inflammation into the iliopsoas compartment. Because data on this entity are derived almost exclusively from isolated case reports and small case series, the current literature provides a fragmented understanding of its clinical behaviour, microbiology, and optimal management. The aim of this study was to summarize the available data on the clinical presentation, diagnostic methods, microbiological profile, treatment plans, and results of IPA in patients with CD by methodically reviewing and analyzing published case reports and case series. This systematic review was registered with PROSPERO (CRD420251164473) and carried out in accordance with PRISMA 2020 principles. To find relevant studies, a thorough search of PubMed, Scopus, Web of Science, and Google Scholar was conducted through February 2025. Case studies and case series describing CD patients who created an IPA were included. Data on demographics, clinical features, diagnostics, microbiology, management, and outcomes were extracted from 53 eligible studies. The Joanna Briggs Institute (JBI) critical assessment methods for case reports and case series were used to evaluate the methodological quality of the included studies. A total of 53 studies including information on 86 individuals were included, comprising 38 case reports and 15 case series. The mean patient age was 30.5 ± 12.9 years, and 55/86 (64.0%) were male. Fever (25/86; 29.1%), abdominal pain (18/86; 20.9%), and combined hip/flank/back pain (23/86; 26.7%) were the most frequently reported presenting features. Cross-sectional imaging was the cornerstone of diagnosis; CT was the most commonly utilised modality (56/86; 65.1%), followed by ultrasound (55/86; 64.0%) and MRI (52/86; 60.5%); most patients underwent more than one modality during workup. Microbiological data from abscess fluid culture were available in 72/86 patients (83.7%); the majority of isolates were polymicrobial enteric organisms, with Escherichia coli being most frequently identified. Management was typically combined: medical therapy (mainly antibiotics) was documented in 68/86 (79.1%) and surgical or interventional management in 78/86 (90.7%). The overall recovery rate was good, although recurrence was observed—particularly in patients treated with drainage alone without addressing the underlying intestinal disease. IPA is a complication of CD that frequently presents with non-specific symptoms, leading to diagnostic delay. Cross-sectional imaging and a high index of suspicion are essential for early diagnosis. Improving clinical outcomes and preventing recurrence require a multidisciplinary approach that includes aggressive source control through drainage, appropriate antimicrobial therapy, and definitive management of the underlying CD, which frequently includes surgical resection and the subsequent consideration of biologic therapy. Not applicable.