Pseudomonas botryomycosis.

A patient had cutaneous botryomycosis due to Pseudomonas aeruginosa. The diagnosis of botryomycosis was based on the clinical manifestations, results of bacterial culture, and demonstraction of the Gram-negative organisms by tissue Gram stain of the granules in the dermis and subcutaneous fat. Numerous laboratory tests, including tissue immunofluorescence and special studies with the patient's lymphocytes, failed to demonstrate an abnormality that might help to explain the pathogenesis of the granular tissue reaction in this patient.