Pyoderma gangrenosum and inflammatory bowel disease: Recent insights into epidemiology, pathogenesis, and therapeutic approaches. Original paper

What was studied?

This review investigates the association between pyoderma gangrenosum (PG) and inflammatory bowel disease (IBD), a rare but significant extraintestinal manifestation. The study covers epidemiology, clinical features, risk factors, and treatment responses of PG in patients with IBD. The article synthesizes data from 115 published case reports and series, focusing on the epidemiological features of PG in both adult and pediatric populations. It also evaluates therapeutic approaches, highlighting the growing use of biologics and the complex nature of treatment, which varies depending on the severity and individual patient response.

Who was studied?

The reviewed articles cover a range of patients with PG and IBD, with a focus on both adults and children. In adult populations, PG is often diagnosed in middle-aged patients, predominantly affecting females. The relationship between PG and IBD has been thoroughly investigated in cohort studies and case series. For children, IBD remains the most common comorbidity with PG, although reports suggest varying presentations based on comorbid conditions and the presence of other immune disorders. This review highlights the diversity in clinical manifestations of PG, with patients presenting at various stages of IBD, sometimes before, during, or after IBD diagnosis.

Most important findings

Recent large cohort studies reveal that the prevalence of PG is significantly higher in IBD patients compared to the general population. The review includes findings from diverse datasets, with IBD being diagnosed in 34% of PG patients. It highlights that PG is more common in patients with Crohn’s disease (CD) than ulcerative colitis (UC). The clinical manifestations of PG are highly variable, but they most commonly involve ulcerative lesions that appear on the extremities, particularly below the knee. Treatment outcomes also show considerable variation, with most patients requiring systemic therapies like corticosteroids, immunosuppressants, or biologics. The review underscores the evolving therapeutic strategies, especially the increasing use of TNF-α inhibitors, reflecting efforts to target overlapping inflammatory pathways between PG and IBD.

Key implications

The study emphasizes the importance of recognizing PG as a significant clinical challenge in managing IBD patients, particularly due to its complex and varied clinical presentation. While biologics have become central to the treatment of PG, the individualized nature of therapy suggests that current approaches are still not standardized. The findings call for better diagnostic criteria and more controlled studies to establish definitive treatment protocols and to understand the underlying pathophysiological mechanisms linking PG to IBD. There is a critical need for multi-center, prospective studies that can overcome the limitations of the available data, such as reporting bias and small sample sizes, to help refine treatment strategies and improve patient outcomes.