Limb Salvage Using Negative Pressure Wound Therapy and Split-Thickness Skin Grafting for Polymicrobial Ecthyma Gangrenosum in a Patient With Acute Lymphoblastic Leukemia: A Case Report.

Ecthyma gangrenosum (EG) is a rare and potentially life-threatening cutaneous infection predominantly affecting profoundly immunocompromised patients. Although classically associated with Pseudomonas (P.) aeruginosa, polymicrobial infections may occur and can result in extensive tissue necrosis and limb-threatening defects. Reconstruction in severely immunocompromised patients is particularly challenging when exposed tendons are present. We present the case of a 32-year-old woman with relapsed B-cell acute lymphoblastic leukemia undergoing re-induction chemotherapy who developed profound neutropenia and rapidly progressive necrosis of the left dorsal hand and forearm following low-energy blunt trauma. The lesion evolved from a post-traumatic hematoma into a 20 × 8 cm full-thickness necrotic defect. Tissue cultures demonstrated polymicrobial infection with P. aeruginosa, Acinetobacter baumannii complex, Stenotrophomonas maltophilia, and extended-spectrum β-lactamase-producing Escherichia coli. Histopathology revealed full-thickness necrosis, dermal vascular thrombosis, and abundant intravascular Gram-negative bacilli, consistent with EG. Management included hematologic optimization, serial surgical debridement, targeted antimicrobial therapy, and negative pressure wound therapy at -125 mmHg. The extensor tendon paratenon was carefully preserved. After 14 days of negative pressure wound therapy and recovery of the absolute neutrophil count to 3.93 × 10³/µL, a healthy granulation bed developed, and definitive coverage was achieved with a split-thickness skin graft harvested from the ipsilateral thigh. Graft take exceeded 95%, with preservation of distal perfusion, sensation, and upper-extremity function. This case demonstrates that extensive polymicrobial EG can be successfully managed with a staged limb-salvage strategy integrating aggressive infection control, negative-pressure wound therapy, hematologic recovery, and delayed skin grafting. Notably, preserving the extensor tendon paratenon can enable successful split-thickness skin grafting in select patients with tendon exposure, thereby avoiding the morbidity of flap reconstruction.