Abstract
Pyoderma gangrenosum (PG) is a rarely diagnosed non-infectious neutrophil ulcerative dermatosis with only limited knowledge on the underlying auto-inflammatory process. To unravel common cofactors and comorbidities in patients with PG we analysed Diagnosis Related Groups (DRG) cases of all inpatients diagnosed with PG in German hospitals in 2012. We received data of 1227 inpatient cases having PG as primary diagnosis and 985 inpatient cases with PG as secondary diagnosis. The ratio of women to men was 2:1, and the most often registered age was 75-79 years. Common comorbidities were arterial hypertension (50·3%), non-insulin-dependent diabetes mellitus (25·1%) and dysfunction of lipid metabolism (10·8%). In sum, 94·8% of the patients suffered from aspects of metabolic syndrome. Other comorbidities were Crohn's disease (4·5%), ulcerative colitis (4·2%), chronic polyarthritis (5·2%), monoclonal gammopathy or myelodysplastic syndrome (2·5%), leukaemia (1·1%) and lymphoma (0·4%). DRG data do not reflect individual patients, but rather patient cases. We described the worldwide largest PG population and confirmed a wide range of potentially relevant and partly not yet described cofactors and comorbidities such as metabolic syndrome.