A 26-year-old man was admitted with a 6-hour history of rapidly developing erythematous, severely painful, mildly to moderately edematous skin rash. The rash started from his right lower back and spread within hours to include the right hip, abdomen, and groin, and down to the proximal third of the anterior lateral aspect of right thigh. At the time of initial infectious diseases consultation, the skin lesion had further spread from the upper third of his right thigh to the upper edge of his right knee over the course of 40 minutes. The patient complained of extreme fatigue; however, he denied any fever, nausea, vomiting, coughing, shortness of breath, dysuria, or sick contacts. He also denied any history of allergy, tobacco use, alcohol consumption, or intravenous drug use. His medical history revealed a history of a mixed connective tissue disease (limited systemic sclerosis overlapping with polymyositis and SLE which had been diagnosed one month previously). He was currently being treated with intravenous immune globulin (IVIG) every three months and prednisone 40 mg daily. He had received a pulse infusion of 1 gram of cyclophosphamide 18 days prior to the current presentation.
His initial vital signs were stable, with temperature of 36.2 C, blood pressure of 123/82 mmHg, heart rate of 114/min, respiratory rate of 22/min, and oxygen saturation of 92% on room air. The patient was alert and oriented. Further physical examination revealed marked erythema over his right lower back, right hip, abdomen, and groin area, as well as the anterior lateral aspect of right thigh. The overlying skin was warm, mildly edematous, and extremely tender when palpated. No sign of crepitus was identified. The patient was neurovascularly intact in both lower limbs. Laboratory studies included a white blood cell count of 6.0 x 109/L, absolute neutrophil of 5.8 x 109/L with left shift noted, hemoglobin of 94 gm/L, platelets of 174 x 109/L, sodium of 130 mmol/L, potassium of 4.1 mmol/L, creatinine of 58 mumol/L, lactate of 2.9 mmol/L, creatine kinase of 661 U/L, and C-reactive protein of 99 mg/L. His hepatic profile revealed elevated alanine aminotransferase of 83 U/L and alkaline phosphatase of 321 U/L. Coagulation study showed normal prothrombin time and an elevated partial thromboplastin time of 47 seconds (22-35 seconds).
The patient was empirically started on piperacillin-tazobactam 4.5 gm IV every 6 hours and vancomycin 500 mg IV every 12 hours which cover broadly for Gram negative and Gram positive organisms including methicillin-resistant Staphylococcus aureus (MRSA), along with clindamycin 600 mg IV every 8 hours. Clindamycin was given to inhibit the toxin production from possible invasive Streptococcus pyogenes based on available human and animal studies. One dose of IVIG was given since he was due for his routine dose for his rheumatological disorders, and given that IVIG may improve outcomes of necrotizing fasciitis from GAS infection. Tissue biopsy of fascia from the anterior and lateral side of right thigh was performed by the orthopedic surgery team at the bedside under local anesthesia and was sent for urgent frozen section pathology and microbiology. Both tissue and blood sample cultures grew Streptococcus pneumoniae sensitive to penicillin. Pathological findings with heavy neutrophilic infiltration and abundant necrosis within fat and fascia were consistent with necrotizing fasciitis. Contrast computerized tomography of the abdomen and pelvis was performed after tissue biopsy suggesting postbiopsy changes without obvious infection involving fascia or muscles. Based on the patient's rapidly developing clinical symptoms and evidence of necrotizing fasciitis on tissue biopsy, he was taken to the operating room urgently. During surgery, he was found to have extensive edema of his subcutaneous tissue, but with no obvious fascial or muscle necrosis. Therefore, no debridement was performed. Fascial tissue from the anterior and lateral side of right thigh was randomly sampled intraoperatively and clear evidence of necrotizing fasciitis with significant neutrophilic infiltration and necrosis in fat and fascia was confirmed by pathological results, as shown in Figure 1. Clindamycin and vancomycin were discontinued on the second day after the microbiology culture results became available. Piperacillin-tazobactam was switched to ceftriaxone which was continued to complete the course of 6 weeks of treatment. The patient required 8 days of postoperative ICU stay which was complicated by methicillin-sensitive Staphylococcus aureus (MSSA) pneumonia, coagulopathy with factor XI deficiency, and a flare-up of his rheumatologic condition. He recovered well with subsequent physiotherapy on the medicine ward and later in the rehabilitation unit.