When infection isn't infection.

Following open reduction and internal fixation for a proximal humerus fracture a 71-year-old man re-presented with wound changes consistent with infection and elevated inflammatory markers. No significant improvement was seen with concomitant intravenous antibiotics and multiple debridement procedures. This case was further complicated by soft tissue breakdown at the site of a left thigh haematoma also requiring debridement. Surgical site infections represent the most common cause of morbidity postoperatively. This case highlights the importance of considering a number of differential diagnoses. A diagnosis of pyoderma gangrenosum prompted systemic corticosteroid therapy giving rapid clinical improvement.