Supplementary Material for: Clinical Disease Patterns in a Regional Swiss Cohort of 34 Pyoderma Gangrenosum Patients

Background/Aim: Pyoderma gangrenosum (PG) is a rare, neutrophilic dermatosis often associated with an underlying disease, and clinical data or larger studies are rare. Methods: In this retrospective study, disease characteristics, clinical manifestations, and treatment response were evaluated in a Swiss cohort of PG patients. Results: In participating centers, 34 cases (21 females) of PG were analyzed based on clinical and histological presentation between 2002 and 2012. The mean age at diagnosis was 61.2 years; 50% of the patients experienced only 1 episode of PG. In 13 cases (out of 20), recurrences occurred during PG therapy; 64.1% showed only 1 lesion simultaneously. The predominant localization was the lower limb (67%). The lesions were disseminated in 26.6%. At the time of diagnosis or recurrence, the mean diameter was 37.6 mm and the mean ulcer size was 10.3 cm2. C-reactive protein (CRP) was elevated in 73.2%; leukocytosis was present in 58.9% and neutrophilia in 50.9%. At least 1 associated comorbidity was present in 85% (the most prominent being cardiovascular disease). The most often used systemic treatments were steroids (68.3%), cyclosporine A (31.7%), dapsone (31.7%), and infliximab (13.3%), and the most often used topicals were tacrolimus 0.1% (48.3%) and corticosteroids (35%). PG healed completely at discharge in 50.8%. The average time to diagnosis was 8 months, and the mean duration to healing was 7.1 months. Conclusion: PG is a difficult-to-diagnose skin disease. Here, markers for inflammation such as CRP, leukocytosis, and neutrophilia were elevated in 50-73% of the PG patients.