Pyoderma Gangrenosum and Systemic Treatment

Pyoderma gangrenosum (PG) is a rare disease where a person's own immune system causes painful skin ulcers, due to a complex and poorly understood mechanism. PG is extremely rare, affecting 3–10 people per million people per year globally; however, when it does occur it bears significant impact on quality of life and increases the risk of death. Current treatment includes a combination of systemic steroids (systemic meaning taken inside the body rather than applied to the skin), immune suppressing drugs, and topical (applied to the skin) treatments, but after decades of research we still do not know the best (or “gold‐standard”) treatment regimen. In this study, authors from Canada aimed to systematically review all of the available research evidence on systemic treatments for PG in order to determine the best treatment regimen. After critically reviewing 3326 research studies, 41 studies were deemed relevant to this research question. What they found was that systemic corticosteroids, cyclosporine, and biologic agents were most commonly studied and were most effective at treating PG. Often, these were combined with topically applied drugs such as steroid cream. Nonetheless, amongst included studies, there was a low cure rate of 15–50% after months of treatment; while cure was sometimes achieved after two to four months, there was a high rate of recurrence of ulcers. Furthermore, the authors found that most studies on PG therapies are of poor quality and thus call for higher quality research in this field.