Favorable outcome of amphotericin B treatment of zygomycotic necrotizing fascitis caused by Apophysomyces elegans

A 45-year-old man was referred from a primary health care center to our hospital in November 2005 with features of necrotizing fascitis of the right shoulder and upper back. He had been admitted to the previous hospital following an injury, sustained in an accident, while driving a tractor. He was treated for fracture of the right clavicle followed by wound debridement of the right shoulder at the health center. Examination of the wound in our hospital revealed a large, 15 x 15 cm, raw area over the upper back, extending to the right upper arm and shoulder. The wound was grossly infected with slough and purulent discharge. The margin of the wound was indurated. No other abnormality was detected on general examination, except for the fracture of the clavicle. Laboratory investigation revealed a hemoglobin level of 7.5 g/dL and a total leukocyte count of 19,600/mm(3), with a differential count of 82% polymorphs, 16% lymphocytes, and 2% eosinophils. The blood glucose was 80 mg%, blood urea 36 mg/dL, and serum creatinine 0.9 mg/dL. Culture of a sample of tissue from the wound yielded a mixture of Escherichia coli, which was sensitive to imipenem, cefoperazone/sulbactam, and amikacin, and resistant to ampicillin, gentamicin, cefazolin, cefotaxime, ticarcillin, ofloxacin, amoxyclavulanic acid, and ciprofloxacin, together with a multidrug-resistant Pseudomonas aeruginosa, which was sensitive to imipenem only. As the patient had features of impending septicemia, he was managed with daily cleaning of the wound, with intravenous imipenem 500 mg eight hourly. Seven days later, the wound showed pockets of white cheesy material extruding out as strands. Microscopic examination of scrapings from this cheesy material showed broad aseptate hyphae suggestive of a zygomycete (Fig. 1). A culture of the tissue on Sabouraud's dextrose agar (SDA) yielded a white fluffy growth after 48 h of incubation at both 25 degrees C and 37 degrees C (Fig. 2a). The microscopic morphology of the fungus stained with lactophenol cotton blue revealed broad, ribbon-like, aseptate hyphae. Sporulation was very poor on the routine SDA medium. Stimulation of sporulation was attempted on 1% water agar.(1) After 1 week of incubation, sporulation occurred, and microscopy revealed a sporangiophore measuring around 200-300 mu m in length, arising at right angles with a septate basal segment, or foot cell, as it is called. The sporangia were multispored, small (20-50 mu m in diameter), typically pyriform in shape, and with hemispherical columellae. The apophysis was funnel shaped (Fig. 2b). The fungus was identified as A. elegans on the basis of these characteristic features. After confirmation of the zygomycotic infection, intravenous amphotericin B, 25 mg, was given on alternate days, as the patient showed an elevated serum creatinine level. Wound debridement was performed twice, followed by local application of gentian violet daily, and a full course of imipenem was given, followed by cefoperazone/sulbactam, 1 g 12 hourly for 2 weeks. Five units of blood were given during this period. This regimen improved the wound remarkably. Split-thickness skin grafting was performed 15 days later. A complete take of the graft with healthy skin was achieved. The patient was discharged in good general condition.