Xanthomonas maltophilia infection presenting as erythematous nodules.

Xanthomonas (Pseudomonas) maltophilia is increasingly being recognized as an opportunistic pathogen in hospitalized and debilitated patients. We describe X. maltophilia cellulitis in a neutropenic patient undergoing consolidation chemotherapy for acute lymphocytic leukemia. The patient had multiple, erythematous, nonulcerated nodules on the lower extremities. A biopsy specimen showed numerous gram-negative bacilli in the dermis and subcutis, without evidence of vasculitis. Tissue culture and subsequent blood cultures grew X. maltophilia. The cutaneous nodules and positive blood cultures resolved after treatment with intravenous ciprofloxacin and trimethoprim-sulfamethoxazole.