Patients with pyoderma gangrenosum experience higher mortality rates

Patients with pyoderma gangrenosum are at greater risk of all-cause and cause-specific mortality compared with the general population, according to a cohort study.

“Pyoderma gangrenosum is a relatively rare neutrophilic dermatosis that is characterized by rapid development of sterile pustules and painful skin ulcers,” Solam Lee, MD, PhD, dermatologist, epidemiologist and clinical assistant professor at Yonsei University Wonju College of Medicine in Wonju, Korea, and colleagues wrote. “Pyoderma gangrenosum has been reported to be associated with other systemic diseases, such as inflammatory bowel disease, rheumatoid arthritis, hematologic disorders, and cancers. ... but to our knowledge, studies on [pyoderma gangrenosum] are scant.”

This population-based cohort study, conducted over a 17-year span, evaluated the association between all-cause and cause-specific mortality in 3,386 patients with pyoderma gangrenosum (PG) compared with 67,720 controls. Patients were matched for age, sex, insurance type and income level.

After adjusting for smoking, drinking, BMI and comorbidities, results showed all-cause mortality was significantly higher in patients with PG vs. controls (adjusted HR = 2.122; 95% CI, 1.971-2.285), excluding those patients with self-harm and psychiatric conditions.

The researchers further found that patients with PG vs. controls faced greater mortality of hematologic disease (aHR = 12.298; 95% CI, 3.904-38.734), connective tissue disease (aHR = 8.685; 95% CI, 4.963-15.199), endocrine disease (aHR, 6.322; 95% CI, 5.026-7.953), infectious disease (aHR = 3.855; 95% CI, 2.640-5.628), kidney/urogenital disease (aHR = 3.617; 95% CI, 2.488-5.259), gastrointestinal disease (aHR = 2.278; 95% CI, 1.522-3.408), 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) and neoplasm/oncologic disease (aHR = 1.618; 95% CI, 1.363-1.92).

When accounting for the 10 leading causes of death, disease-specific mortality was also greater in patients with PG vs. controls for myocardial infarction (aHR = 3.043; 95% CI, 2.111- 4.386), pneumonia (aHR = 2.096; 95% CI, 1.511-2.908), ischemic stroke (aHR = 1.937; 95% CI, 1.206-3.112), liver cirrhosis (aHR = 2.645; 95% CI, 1.47-4.761) and diabetes (aHR = 6.494; 95% CI, 5.128-8.224).

According to the study, PG 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 compared with idiopathic PG (aHR = 2.062; 95% CI, 1.897-2.241). PG associated with inflammatory bowel diseases, however, showed a better prognosis (aHR = 1.742; 95% CI, 0.964-3.148) vs. idiopathic PG.

In comparing 5-year and 15-year survival rates for patients with PG, these rates dropped from 84.5% to 53.1%, respectively, whereas controls experienced a drop from 93.8% to 71.8%.

Since all data was attained from ICD-10 codes in NHIS claim data, the researchers called the lack of detailed clinical information that could have been used to identify subtypes and severity of diseases a limitation to this study.

“To improve the long-term prognosis, a multidisciplinary approach might be required because PG is associated with various systemic diseases and is not a local disease that is confined to the skin,” the researchers wrote.