Kridin K, et al. - Experts sought to synthesize existing data on the prevalence of associated systemic diseases in patients with pyoderma gangrenosum. As per results, a relevant underlying disease was seen in more than half of patients with pyoderma gangrenosum. Most frequently associated diseases were inflammatory bowel disease and arthritis. The pooled prevalence of arthritis and hematological malignancies was lower while the pooled prevalence of solid malignancies was higher relative to the reported literature. Results ought to be interpreted with caution owing to the high level of heterogeneity among most of the comparisons.