The Association of Age With Clinical Presentation and Comorbidities of Pyoderma Gangrenosum.

IMPORTANCE: Pyoderma gangrenosum is an inflammatory neutrophilic dermatosis. Current knowledge of this rare disease is limited owing to a lack of validated diagnostic criteria and large population studies.

OBJECTIVE: To evaluate the association of age with the clinical presentation and comorbidities of pyoderma gangrenosum.

DESIGN, SETTING, AND PARTICIPANTS: This was a multicenter retrospective cohort study performed at tertiary academic referral centers in urban settings. Adults (≥18 years) who were evaluated and diagnosed as having pyoderma gangrenosum at the Brigham and Women's and Massachusetts General Hospitals from 2000 to 2015 and the University of Pennsylvania Health System from 2006 to 2016 were included.

MAIN OUTCOMES AND MEASURES: Patient demographics, clinical features, medical comorbidities, and treatment.

RESULTS: Of the 356 validated cases of pyoderma gangrenosum included in the study, 267 (75%) were women and 284 (84.8%) were white. The mean (SD) age at presentation was 51.6 (17.7) years. Pathergy was recorded in 100 patients (28.1%). A total of 238 patients (66.9%) had associated medical comorbidities: inflammatory bowel disease in 146 patients (41.0%); inflammatory arthritis in 73 patients (20.5%); solid organ malignant neoplasms in 23 patients (6.5%); hematologic malignant neoplasms in 21 patients (5.9%); and hematologic disorders, specifically monoclonal gammopathy of undetermined significance, myelodysplastic syndrome, and polycythemia vera in 17 patients (4.8%). When stratified by age, pathergy was more common in patients 65 years or older (36.3% vs 24.3%; P = .02). Inflammatory bowel disease was the only medical comorbidity that was more common in patients younger than 65 years (47.7% vs 26.6%; P < .001), while a number of medical comorbidities were more common in those 65 years or older, including rheumatoid arthritis (13.3% vs 6.2%; P = .03), ankylosing spondylitis (1.8% vs 0%; P = .04), solid organ malignant neoplasms (13.3% vs 3.3%; P < .001), hematologic malignant neoplasms (9.7% vs 4.1%; P = .04), and the aforementioned hematologic disorders (10.6% vs 2.1%; P < .001).

CONCLUSIONS AND RELEVANCE: Although clinical presentation in this large cohort was similar between different age groups, disease associations varied by age. The findings of this study may allow for a more focused, age-specific evaluation of patients with pyoderma gangrenosum.