Pyoderma gangrenosum: a retrospective review of patient characteristics, comorbidities and therapy in 103 patients.

BACKGROUND: Pyoderma gangrenosum (PG) is an uncommon and challenging disease, highly associated with comorbidities, but poorly characterized from a diagnostic and therapeutic perspective.
OBJECTIVES: To describe the epidemiology of PG in a hospital-based retrospective review, focusing on demographics, comorbidities and treatments.
METHODS: We conducted a retrospective chart review. Patient data were taken from the Research Patient Data Repository of Brigham and Women's Hospital and Massachusetts General Hospital from 1 January 2000 to 31 December 2007. We identified and confirmed 103 cases of PG, and collected data on anatomical location, number and size of the PG lesions, patient demographics, comorbidities, mortality rate and treatments.
RESULTS: Of the 103 patients, 78 (76%) were female, and only 7% had a biopsy suggestive of PG. The lower leg was the most common location with 78% of PG ulcers occurring there, and 67 (65% of patients) had two or more ulcers at some point. Thirty-five individuals (34%) had inflammatory bowel disease (IBD), 21 (20%) had haematological disorders, 14 (14%) had major depression, 20 (19%) had seronegative arthritis, 11 (11%) had psoriasis, and nine (9%) had hepatitis. Therapy was generally multimodal. The mortality rate during the 8-year study period was 16%.
CONCLUSIONS: We present one of the largest PG case series to date. In our study, we found that biopsy of a PG lesion rarely yielded characteristic features of the disease and tissue pathology should not be used to exclude a PG diagnosis. We also found a female predominance and associations with IBD and haematological disorders. Patients with PG in this series had high rates of depression and hepatitis. Further work is needed to establish the mechanism(s) underlying these findings.