Perianal Abscess as a Potential First Manifestation of Crohn’s Disease - Current State of Knowledge

Abstract

Introduction and Purpose

Perianal abscess (PAA) may precede the diagnosis of Crohn’s disease (CD), even without typical intestinal symptoms. However, most PAAs are unrelated to CD, making it difficult to identify patients who require further investigation. This review evaluates PAA as a potential early manifestation of CD and summarizes features that may increase suspicion of underlying disease.

Materials and Methods

A structured PubMed/MEDLINE search was performed, with the final search completed on 12 August 2026. Studies on PAA, perianal fistula (PAF), early CD recognition, diagnostic assessment, and disease course were included. PAA-specific evidence was considered separately from mixed PAA/PAF and PAF-only studies.

Results

The risk of subsequent CD after a first isolated PAA remains uncertain, and most available evidence derives from fistula or mixed perianal cohorts. Gastrointestinal symptoms, recurrent or atypical perianal disease, inflammatory abnormalities, selected imaging findings, and elevated faecal calprotectin may increase suspicion. No PAA-specific risk model or diagnostic strategy has been prospectively validated.

Conclusion

A first isolated PAA may represent an early manifestation of CD but cannot reliably distinguish Crohn-related from cryptoglandular disease. Further assessment should be guided by the overall clinical context and disease course. Prospective PAA-specific studies are needed to define risk and identify patients who may benefit from early CD evaluation.