Necrotizing Fasciitis Caused by Gas-producing Methicillin-sensitive Staphylococcus aureus: A Case Report

Abstract

Introduction: It is well known that diabetic patients have impaired wound healing, increased susceptibility to infection, and harbor tissue that supports the growth of gas-producing infections. Necrotizing fasciitis (NF) is an uncommon soft-tissue infection characterized by extensive necrosis of subcutaneous tissue and fascia with relative sparing of the skin and muscle tissues. The majority of gas-producing infections are polymicrobial in nature, and therefore, NF with Staphylococcus aureus as a single etiologic agent is exceedingly uncommon.

Case report: This is a case of a 46-year-old male that developed gas-forming NF and abscesses from methicillin-sensitive S. aureus (MSSA) after a complicated course involving undiagnosed type 2 diabetes mellitus (T2DM), diabetic ketoacidosis, and bacteremia. The disease course presented relatively slowly with mild systemic symptoms, knee pain, erythema, and edema, but steadily progressed over days leading to an elevated level of care. Multidisciplinary care was necessary to treat the patient, including surgical and intravenous antibiotic therapies. The patient's care was prolonged due to decreased patient compliance with recommended therapies and difficulty with appropriate shared decision-making.

Conclusion: Although NF caused by monomicrobial infection with methicillin-resistant S. aureus has been previously reported, awareness of this condition remains limited, especially with concomitant gas formation. Physicians should have a high index of suspicion for NF with MSSA as a potential etiologic agent when treating patients with symptoms of a necrotizing soft-tissue infection, particularly those with underlying T2DM or a history of recent needle puncture. By engaging in shared decision making, health outcomes in these serious infections can be optimized.

Keywords: Necrotizing soft-tissue infection; infectious disease; shared decision-making; wound care; wound vacuum-assisted closure therapy.

Figure 1

Day 15: Original computed tomography (CT) scan coronal (a) and axial (b and c) CT scan images of our patient upon presentation, revealing multiple small intramuscular abscesses depicted by the arrows. Diffuse edema is also seen in soft tissues.

Figure 2

Day 15: Clinical appearance of left leg clinical appearance of left leg upon presentation to neighboring hospital emergency department with minimal erythema but significant edema throughout the medial, anterior, and lateral distal thigh as evidenced by finger indention (arrow) on medial thigh.

Figure 3

Day 26: Radiograph of left knee showing soft tissue gas anteroposterior (a) and lateral (b) X-rays of the patient’s left knee upon presentation to the neighboring hospital, revealing significant soft-tissue swelling and subcutaneous and intramuscular emphysema along the lateral and anterior distal thigh.

Figure 4

Day 26: Magnetic resonance imaging (MRI) left lower extremity confirming gas foci axial (a and b) and sagittal (c and d) MRI images revealing an intra-articular knee effusion and contiguous suprapatellar and distal thigh fluid collection with multiple foci of gas.

Figure 5

Day 26: Computed tomography (CT) left lower extremity confirming gas foci coronal (a) and axial (b and c) CT scan images revealing multiple foci of gas tracking proximally along fascial plane to proximal femur, large intermuscular multiseptated fluid collection in anterior thigh compartment, and diffuse soft-tissue edema.

Figure 6

Day 26: Computed tomography (CT) chest showing gas foci axial CT scan of chest demonstrating intramuscular gas-forming abscess in left infraspinatus muscle.

Figure 7

Day 26: Original thigh irrigation and debridement intraoperative fluid appearance. Murky, purulent fluid was encountered immediately after making an incision through the lateral arthroscopic knee portal site and extending proximally through subcutaneous tissue.

Figure 8

Day 26: Depiction of extensive purulence from left lower extremity lateral thigh incision after evacuation of gross purulence, revealing with necrotic fascia before debridement (a) and some of the purulence collected from the thigh (b).

Figure 9

Granulation tissue before skin grafting images of the patient’s left lateral thigh wound with healthy granulation tissue (a) after serial wound vacuum changes and healing lateral thigh wound and anterior thigh donor site wounds after split-thickness skin graft procedure (b).

Figure 10

Final surgical wound appearance after skin grafting pictures (a, b, c) of the patient’s healed leg wounds at the present time.