Pyoderma gangrenosum induced by transcutaneous electrical nerve stimulation: a case report with literature review.

Pyoderma gangrenosum (PG) is one of the neutrophilic dermatosis, a heterogenous group of rare inflammatory diseases affecting the skin. It is often associated with systemic diseases such as inflammatory bowel disease, rheumatoid arthritis or hematological malignancies. Classical PG is characterized by painful ulcers with violaceous, undermined border, often developing at sites of injury because of the typical pathergy phenomenon. Because of its polymorphic presentation, misdiagnosis and delayed diagnosis are common. We present a case of PG occurring after transcutaneous electrical nerve stimulation (TENS) in a young female patient with ulcerative colitis. Although electric current has previously been incriminated as a trigger for PG, to the best of our knowledge this is the first case precipitated by TENS. We report a typical case of PG occurring after an unusual stimulus and highlight the challenges that the diagnosis of this relatively rare pathology poses to the clinician.