Background: Pyoderma gangrenosum (PG) is an inflammatory disease characterized by painful ulcerations. It is often associated with other systemic inflammatory diseases, especially inflammatory bowel disease (IBD) and autoimmune arthritis.
The problem: PG does not have characteristic serologic or histologic features. Therefore, other potential causes such as malignancy, vasculitis, infection, and coagulation disorders should be ruled out. In addition, patients often have aggressive disease that is refractory to immunosuppressive therapy, but there is only a paucity of clinical data to help direct therapy.
Basic/clinical science advances: There are several lines of evidence to support an immunologic etiology of PG. Although the pathogenesis is still not well understood, it is clear that PG is associated with the upregulation of several cytokines including interleukin 8 (IL-8), tumor necrosis factor (TNF), IL-1β, IL-6, and interferon gamma, among many others. TNF and IL-1β are of particular interest, because some biologic medications that target these cytokines have been effective in treating PG.
Clinical care relevance: Multiple drugs are available to help control PG. Biologics, intravenous immunoglobulin (IVIG), and conventional immunosuppressive drugs have been reported to be effective. Multidrug therapies should be considered for refractory cases.
Conclusion: PG is a complex inflammatory disease with multiple involved pathways. Anti-TNF agents and IVIG represent a significant advancement in treatment options. Since some biologic therapies are relatively new, their unknown long-term side effects should be taken into consideration.