Underlying Systemic Diseases in Pyoderma Gangrenosum: A Systematic Review and Meta-Analysis.

More than half of patients with pyoderma gangrenosum present with a relevant underlying disease. Inflammatory bowel disease and arthritis are the most frequently associated diseases. Relative to the reported literature, the pooled prevalence of arthritis and hematological malignancies is lower, while the pooled prevalence of solid malignancies is higher. Owing to the high level of heterogeneity among most of the comparisons, results should be interpreted with caution.