Bullous necrotizing cellulitis in kidney transplant recipient

The patient is a 68-year-old male with a history of chronic kidney disease of unknown cause. He received a kidney transplant 25 years ago and was treated with double immunosuppression therapy with everolimus and methylprednisolone. He also has a history of multiple tumours (skin and parotid). The patient presented to the emergency department with a 10-day history of fever associated with pain, swelling and erythematous lesions in the middle third of the right leg. The patient denied previous history of local trauma, abdominal pain and urinary symptoms. During admission, these lesions progressed to bullae with serum-haematic content, which subsequently formed necrotic background ulcers with irregular borders, exposing the underlying muscle tissue (Figure 1A and B). Blood and ulcer secretion cultures were performed, with isolation of Escherichia coli, initiating treatment with intravenous meropenem. The necrotic lesions were surgically debrided (Figure 1C), and free skin grafts were performed to correct the defects of the skin. Infectious process was controlled within 1 month of systemic antibiotic therapy and achieved complete cure of the lesions with discharge at 45 days after admission. Bullous necrotizing cellulitis is an infection caused in most cases by E. coli, mainly in immunocompromised patients. This serious complication has been previously described in childhood nephritic syndrome, diabetes mellitus and haemodialysis patients, but this is the first case described in a kidney transplant recipient. The estimated mortality of this entity is ~50% and treatment consists of prolonged antibiotic therapy against gram-negative micro-organisms and occasionally surgical repair of necrotic tissues may be required. This kind of serious infectious complication must be taken into account in kidney transplant patients with torpid evolution cellulitis.