Purpose of review
To describe current progress in understanding pyoderma gangraenosum, illustrate clinical observations and discuss therapeutic interventions.
The proline-rich, glutamic acid-rich, serine-rich and threonine-rich (PEST) family of protein tyrosine phosphatases is a critical regulator of adhesion and migration. PSTPIP1 is a cytoskeleton-associated adaptor protein that links PEST-type phosphatases to their substrates. This pathway seems to be involved in diseases related to pyoderma gangraenosum such as chronic inflammatory bowel disease and aseptic abscesses syndrome. Pyoderma gangraenosum is one of the most common extra-intestinal manifestations of chronic inflammatory bowel disease. In multivariate analyses, pyoderma gangraenosum was significantly and independently associated with black African origin, familial history of ulcerative colitis, uninterrupted pancolitis as the initial location of inflammatory bowel disease, permanent stoma, eye involvement and erythema nodosum. The treatment of choice for idiopathic pyoderma gangraenosum is systemic corticosteroids but cyclosporine A, mycophenolate mofetil and tumour necrosis factor-alpha inhibitors have been successful to control pyoderma gangraenosum as second line or adjuvant options. In addition, small studies have been published with successful therapeutic intervention using alefacept, visilizumab or anakinra but controlled trials are warranted. Although systemic immunosuppressants remain the choice therapy for most cases of pyoderma gangraenosum, a local approach should be considered in localized disease. Recently, topical tacrolimus has successfully been used as an off-label drug in localized disease.
By a better understanding of the underlying pathology and recent drug developments patients with pyoderma gangraenosum will benefit. For several new drugs, however, controlled trials are warranted.