Ben Abdallah H, Bech R, Fogh K, et al. - Researchers conducted this nationwide registry nested case-control study to examine the mortality, prevalence and risk of comorbidities in patients with pyoderma gangrenosum (PG). Between January 1, 1994, and December 31, 2016, all inpatients and outpatients diagnosed with PG in tertiary dermatology centres in Denmark were analyzed. In total, 1,604 patients with PG were matched with 16,039 controls. Patients with PG have a higher mortality rate, as well as a higher prevalence and risk of both previously reported and novel comorbidities, which can have serious consequences if undiagnosed. The findings mostly pertain to moderate and severe PG.