Association of All-Cause and Cause-Specific Mortality Risks With Pyoderma Gangrenosum

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis. Few studies have evaluated the mortality outcomes of patients with PG.

To investigate all-cause and cause-specific mortality in patients with PG.

This retrospective population-based cohort study used data from the National Health Insurance Service database of Korea and the National Death Registry of Korea from patients with incident PG (≥3 documented visits with an International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code of L88) during January 2003 to December 2019. For comparison, a 1:20 cohort of age-, sex-, insurance type-, and income level-matched controls without any documented visit with an ICD-10 code of L88 during the entire observation was included.

Pyoderma gangrenosum.

The participants were observed from the index date to their death, emigration, or the end of the observation period to investigate all-cause and cause-specific mortality during the 17-year study period.

In total, 3386 patients with PG (1450 women [42.8%]; mean [SD] age, 57.8 [16.4] years) and 67 720 controls (29 000 women [42.8%]; mean [SD] age, 57.8 [16.3] years) were analyzed. All-cause mortality risk was greater in patients with PG than in controls (adjusted hazard ratio [aHR], 2.122; 95% CI, 1.971-2.285) after adjustment for smoking, drinking, body mass index, and comorbidities. Patients experienced greater mortality of infectious disease (aHR, 3.855; 95% CI, 2.640-5.628), neoplasm (aHR, 1.618; 95% CI, 1.363-1.920), hematologic disease (aHR, 12.298; 95% CI, 3.904-38.734), endocrine disease (aHR, 6.322; 95% CI, 5.026-7.953), neurologic disease (aHR, 2.039; 95% CI, 1.337-3.109), cardiovascular disease (aHR, 1.979; 95% CI, 1.645-2.382), respiratory disease (aHR, 1.757; 95% CI, 1.365-2.263), gastrointestinal disease (aHR, 2.278; 95% CI, 1.522-3.408), connective tissue disease (aHR, 8.685; 95% CI, 4.963-15.199), and kidney/urogenital disease (aHR, 3.617; 95% CI, 2.488-5.259) than controls. Compared with idiopathic PG (aHR, 2.062; 95% CI, 1.897-2.241), PG that was associated with solid organ cancer (aHR, 2.313; 95% CI, 1.956-2.737) and hematologic cancer (aHR, 8.330; 95% CI, 5.473-12.679) showed greater mortality, whereas PG that was associated with inflammatory bowel diseases showed a slightly better prognosis (aHR, 1.742; 95% CI, 0.964-3.148).

The results of this cohort study suggest that patients with PG had a higher all-cause and cause-specific mortality risk than the general population.