Pyoderma Gangrenosum as a Presenting Feature of Undifferentiated Spondyloarthropathy with Erosive Inflammatory Arthritis.

Pyoderma gangrenosum is a rare inflammatory condition with varying clinical presentations and severity. It is commonly seen in association with an underlying condition, most common of which is inflammatory bowel disease. We report a case of a 26-year-old male who came to the emergency department with increasing lower extremity ulcers, intermittent hematochezia, and pain in the small joints of his hands. After excluding a broad list of differentials for lower extremity ulcers, the diagnosis of pyoderma gangrenosum was made. He was also found to have erosive changes at multiple proximal interphalangeal joints and jug-like syndesmophytes at T12 and L1 on CT scan. Although there was evidence of a spondyloarthropathy, there was no evidence of inflammatory bowel disease on colonoscopy, psoriasis, or sexually transmitted infections. After multiple failed trials of medications including azathioprine and sulfasalazine, 4 weeks of Adalimumab resulted in rapid healing of pyoderma gangrenosum lesions and improvement in his synovitis. Coupled together, this suggests a diagnosis of pyoderma gangrenosum associated with undifferentiated spondyloarthropathy and erosive inflammatory arthritis. This case is suggestive of spondyloarthropathy going underdiagnosed and untreated in other patients with pyoderma gangrenosum as lower extremity ulcerations can be the primary complaint for seeking treatment. Although rare, axial spondyloarthropathy associated with pyoderma gangrenosum should be kept as an associated differential diagnosis when faced with pyoderma gangrenosum.