Necrotizing Soft-Tissue Infection: Laboratory Risk Indicator for Necrotizing Soft Tissue Infections Score
A 64-year-old male patient was brought to the surgical OPD of JSS Medical College, Mysore, Karnataka, on the 29th of February, 2013, with the complaints of fever and a painful blackish lesion on the right lower abdomen. Patient was a diabetic, on dietary modification, under glycemic control. He was also a known case of bronchiectasis on treatment with steroids and had visited a local doctor a week back for neuritic type of pain in the right lower abdomen, for which a Diclofenac patch, had been applied by the doctor. Patient noticed pain and swelling in the area 2 days later. When the lesion started spreading and he also began to have spikes of fever, patient was brought to our hospital.\nOn examination, there was a patch of gangrene on the anterior abdominal wall in the iliac region measuring 5 cm × 5 cm. There was pus oozing from a small area of the wound. Patient was febrile; there were no other significant findings except bilateral basal crepitations.\nIn view of the immunocompromised state, the toxicity and the gangrene, possibility of a necrotizing infection was considered and biochemical and hematological workup was ordered. The LRINEC score at the time of admission was 7 as indicated []. Pus was collected and subjected to Gram stain, acid fast stain and bacterial, mycobacterial and fungal cultures were put up. Gram stained smear revealed the presence of plenty of inflammatory cells, Gram positive cocci in chains and Gram negative coccobacilli. There were also a large number of broad aseptate fungal hyphae, suggestive of Zygomycosis. Blood culture (BacT Alert) did not yield any bacterial or fungal growth.\nIn view of the clinical and laboratory findings, the patient was posted for wide excision and debridement. He was started on treatment with Imipenem, Linezolid and also low dose amphotericin B.\nThere was soakage of the dressing on the 2nd day after surgery, there was sloughing of the skin and subcutaneous tissue and pain persisted. Repeat Gram stain showed the same findings. Aerobic bacterial culture yielded the growth of Enterococci sensitive to Linezolid and Acinetobacter sensitive to piperacillin-tazobactam, imipenem, meropenem and amikacin. The bacterial isolates were identified by using Vitek 2 automated system. Anaerobic cultures (Gaspak) did not yield any bacterial growth.\nFungal culture showed a fluffy wooly white colony with no sporulation after 3 days. On slide culture at 25°C and 40°C in biological oxygen demand incubator, sporulation was observed after 10 days. Broad aseptate hyphae with unbranched sporangiophores, prominent funnel shaped apophyses and pyriform sporangia were observed []. Based on thermotolerance (up to 40°C) and morphological features the fungus was presumptively identified as Apophysomyces elegans.\nHistopathological examination (H and E stain) revealed broad aseptate hyphae suggestive of Zygomycosis. The hyphae were periodic acid schiff (PAS) positive. Vascular invasion was observed.\nAntibiotic treatment was continued, repeat LRINEC scores were validated [] and a repeat wider debridement was done. However, the lesion continued to spread relentlessly, the edge of the lesion was black and necrotic muscle tissue was seen in the wound []. Meanwhile patient's respiratory distress also worsened. He was put on oxygen support initially, ventilated later for respiratory distress. Patient succumbed to his illness on the 10th day after admission.