Clinical Significance and Long-Term Prognosis of Appendiceal Orifice Inflammation in Ulcerative Colitis: A Systematic Review.

Appendiceal orifice inflammation (AOI), also described as a peri-appendiceal red patch or cecal patch, is a recognized skip lesion in ulcerative colitis (UC), although its clinical significance and long-term prognostic implications remain uncertain. This systematic review with narrative synthesis, conducted in accordance with PRISMA 2020 guidelines, evaluated the available evidence from comparative observational studies of UC patients with and without AOI. Nine comparative cohort studies published between 2002 and 2022 were included, with sample sizes ranging from 39 to 376 patients. Across the included studies, AOI was most frequently observed in patients with distal or limited UC. Some cohorts reported associations with higher baseline inflammatory activity or lower rates of complete endoscopic remission, while others did not demonstrate significant differences in short-term treatment response. Proximal disease extension emerged as the most consistently reported long-term association, particularly in patients with initial proctitis; however, this finding did not consistently translate into worse overall clinical outcomes. Most studies did not show a clear increase in major adverse outcomes such as hospitalization or colectomy. Findings regarding treatment escalation were variable, with some studies suggesting an increased likelihood of therapy intensification, whereas others found no independent prognostic impact. Overall, AOI appears to be a clinically relevant but heterogeneous finding in UC that does not consistently function as an independent marker of poor long-term prognosis.