Postoperative Group B Streptococcal Necrotizing Fasciitis in a Previously Healthy Child

Necrotizing fasciitis is an unusual infection of the subcutaneous soft tissue and underlying fascia that requires early diagnosis and surgical debridement because of its rapidly progressive course. Previously described risk factors for necrotizing fasciitis include trauma, surgery, chickenpox and underlying conditions such as diabetes.1, 2 The organisms most commonly associated with this destructive disease entity in children are group A Streptococcus, Staphylococcus aureus, enteric Gram-negative organisms, Clostridium sp. and Pseudomonas aeruginosa either as single pathogens or in combination with other aerobic or anaerobic organisms.1 Although group B streptococcal infections are not uncommon during the neonatal period, necrotizing fasciitis is a rare entity even in this age group.3-5 Necrotizing fasciitis caused by group B Streptococcus is extremely rare in the adult population.6-8 Postoperative necrotizing fasciitis is well-described in the literature,9, 10 with group A Streptococcus and Escherichia coli as the commonly involved pathogens. To our knowledge this is the first report of a child with postoperative necrotizing fasciitis caused solely by Streptococcus agalactiae. Case report. A previously healthy 10-year-old Caucasian male fell off of his bicycle and sustained a severe closed supracondylar fracture of the right humerus, necessitating an open reduction and internal fixation. The patient was discharged home on postoperative Day 2 with no signs of wound infection. Later that day and during the next 24 h his temperature reached 39.5°C with the onset of pain and swelling of the right arm. He returned to the hospital with a temperature of 39.6°C, pulse of 107/min and blood pressure of 132/80 mm Hg, with tenderness and swelling on the distal third of his right upper arm. A purple black discoloration and a 1.5-cm bulla in the antecubital fossa were noted. The radial pulse was absent on the right but brisk capillary refill was present. Sensation and movement of the fingers of the right hand were intact. The peripheral white blood cell count was 16 300/mm3 with 79% polymorphonuclear cells and 13% band forms. The hemoglobin was 11.1 g/dl, the platelet count was 145 000/mm3 and the erythrocyte sedimentation rate was 96 mm/h. A plain radiograph of the right elbow revealed soft tissue air. The child was transferred to Children's Hospital for debridement, with findings of necrosis of the skin medial to the antecubital fossa with necrotic fascia and a yellowish, serosanguineous drainage around the incision. Thrombosis of the brachial and radial arteries was noted intraoperatively, requiring thrombectomy. Group B Streptococcus was isolated from the aerobic cultures; cultures for strict anaerobes were negative. Empiric therapy was changed from imipenem to penicillin G (200 000 units/kg/day). The patient subsequently returned to the operating room six more times for further debridement. Tissue cultures from the second, third and fourth procedures were also positive for S. agalactiae and anaerobic cultures were sterile. The patient ultimately returned to the operating room for final debridement procedures on Day 18, followed by plastic surgery with skin grafting. On follow-up examination 4 months later, he has some loss of function but is healing well with no recurrence of infection. Discussion. Necrotizing fasciitis refers to a rapidly progressive infectious destruction of the subcutaneous tissue and fascia that can compromise the overlying skin. The underlying pathogenic process involves the production of destructive enzymes and toxins by the bacterial organisms that allow evasion of the host immune defenses and the spread of the bacteria through the tissue planes resulting in rapid tissue necrosis.1, 6 Reports of group B streptococcal necrotizing fasciitis in children unrelated to a postoperative state have been limited to premature infants who presented with sepsis syndrome within the first few months of life.3, 4 Postoperative necrotizing fasciitis has been reported in adults6 and children9, 10 after a wide variety of surgical procedures. Postoperative group B Streptococcus necrotizing fasciitis is rarely encountered. Only two cases have been reported in adults: a healthy 26-year-old postpartum patient with an episiotomy infection that required extensive resection in addition to antibiotic treatment8; and a 51-year-old diabetic woman with infection following femoropopliteal bypass surgery.7 Necrotizing fasciitis most often occurs between a few hours to several days after surgery,7, 9 marked by fever, erythema, severe tenderness and edema. Initially the skin may not be affected but subsequently blisters and bullae appear and the skin may become gangrenous.1, 7, 9 Roentgenographic studies frequently reveal soft tissue gas.7, 9, 11 Initial management includes hemodynamic stabilization, systemic antibiotics and early aggressive surgical debridement. Extensive debridement of all involved layers of necrotic tissue are necessary for survival. Repeated surgical resection to freely bleeding margins is needed until no devitalized tissues are found after successive procedures.7, 9 To our knowledge this is the first report of group B Streptococcus necrotizing fasciitis arising postoperatively in a previously healthy child. Rolando M. Viani, M.D., M.T.P. Aimee Lewis, B.A. John S. Bradley, M.D.