Perineal pyoderma gangrenosum in pregnancy: A case report.

Pyoderma gangrenosum is a rare ulcerating neutrophilic dermatosis. We describe the case of a 28-year-old woman with pyoderma gangrenosum in the perineal region during pregnancy. Cytological analysis of a skin biopsy specimen showed neutrophilic infiltrates across all the layers of the dermis, confirming the diagnosis of pyoderma gangrenosum. Determining a management plan, including the mode of delivery, was difficult. Oral prednisolone was started and her ulcer started to improve, but she still had the ulcer when she reached full term. Because there was a concern that the ulcer would be worsened by vaginal delivery, cesarean section was performed. After her delivery, pyoderma gangrenosum had not appeared at the cesarean incision and the ulcer in the perineal region had improved. Obstetricians should be aware of pyoderma gangrenosum as a differential diagnosis when vulvar ulceration develops during pregnancy.