P43 – Necrotizing Sweet’s syndrome masquerading as necrotizing fasciitis

Author(s):
John Young, Andrew Stephen, Charles Adams, William Cioffi, Daithi Heffernan, Brown University, Rhode Island Hospital

Background: Necrotizing fasciitis(Nec Fasc) is a rapidly spreading necrotizing infection of soft tissues and fascia requiring surgical debridement. Sweet’s syndrome (acute febrile neutrophilic dermatosis) is characterized by fevers and tender erythematous skin lesions with dermal neutrophil infiltration, often paraneoplastic, responding to systemic corticosteroids. The Necrotizing Sweet’s Syndrome(NSS) subtype, has rapidly progressive lesions, deep-tissue neutrophilic infiltration and soft-tissue necrosis in the absence of an infection.

Hypothesis: NSS mimics Nec Fasc both clinically and pathologically and may lead to harmful surgical debridements.

Methods: We present a case of NSS masqueading as Nec Fasc.

Results: A 34 yr old female presented with a presumed thigh abscess. Despite drainage and antibiotics, she developed shock, rapid wound progression, prompting surgical debridement. Clinical and pathologic features were consistent with Nec Fasc. However culture data was negative. Despite initial wound healing, multiple areas of skin necrosis occurred – original wound, peripheral and central(Image) IV sites, requiring debridement. Pathology was consistent with Nec Fasc. The development of pancytopenia with greater than 70% blasts raised concern for acute myeloid leukemia, confirmed by bone marrow biopsy. The diagnosis of AML, negative cultures and multifocal nature of soft tissue necrosis, led to the consideration of Sweet’s syndrome. Further pathology review noted dermal neutrophilic and atypical mononuclear infiltrate epidermal hyperplasia, spongiosis and neutrophil exocytosis, consistent with Sweet’s syndrome. Steroids were started with prompt fever resolution and wound improvement, and she was transitioned to chemotherapy.

Conclusions: Operative intervention in NSS can lead to disease progression. NSS and Nec Fasc both display rapidly expanding erythematous painful skin bullae. In culture negative patients with delayed progression of necrotizing wounds, alternate diagnoses, such as NSS need to be considered. Communication between surgeon and pathologist is critical.