A 28-year old healthy female was admitted seven days post-operatively following Cesarean section for abdominal wound complications. On admission, she was septic; her scar was tender and erythematous with surrounding purple discoloration. Within a few hours, the edges of her scar turned dusky, extending well outside the originally marked boundaries. Aggressive debridement of the wound ensued and antibiotics were started as the diagnosis of necrotizing fasciitis (NF) was made. Hospitalist service was consulted for medical management. In the ensuing weeks, the patient underwent multiple surgeries and hyperbaric oxygen therapy. Specimens were read as “sheets of necrosis consistent with NF”, and wound cultures initially were positive but persistently negative thereafter. Despite this, her condition worsened, with the wound growing to encompass the entire abdomen and necrosis spreading to the peritoneum. Additional history revealed that her grandmother had PG with a similar presentation. A dermatopathologist was asked to reevaluate the surgical biopsies, and determined them to be more consistent with pyoderma gangrenosum (PG) given clinical history and lack of microscopic bacteria. A high-dose steroid regimen was started; the patient’s status quickly improved and wound gradually receded. A permanent skin graft will be placed once enough granulation tissue has formed.
Discussion:
This case illustrates the difficulty of diagnosing PG and the value of evaluating an existing diagnosis. PG is a condition characterized by intense inflammation. It is a rare and often recurring chronic neutrophilic dermatosis, which often occurs on lower extremities in patients with inflammatory and hematologic disorders. PG lacks specific clinical and histological findings, and diagnosis rests upon elimination of other conditions. Differentiating PG from NF is difficult, as both quickly evolve into extensive ulcerations. The patient had no predisposing conditions. PG resulting from a C-section scar in the absence of other pathergy is uncommon. It is human nature to form judgment based on first impressions. In medicine, this tendency to make clinical decisions heavily based on first piece of information is anchor bias. In hospital medicine, anchoring often happens in cases considered “typical”. Although this cognitive shortcut can help physicians become more efficient clinical decision makers, it can lead to significant error.
Conclusions:
PG is an important dermatologic disorder for hospitalists to be familiar with. It is vital to realize the tendency to rush into making a diagnosis, cling to consultants’ input, and anchor on fixed ideas. When the “classic” cases start to deviate from their usual course, it is time to step away from our cognitive shortcuts.