Pseudomonas aeruginosa skin
infections are generally considered to be secondary manifestations of disseminated disease. A retrospective analysis of all cases of P. aeruginosa skin
infections seen at St. Jude Children's Research Hospital since 1962 revealed 16 episodes of the
infection (
ecthyma gangrenosum, 8 episodes, 7 patients;
cellulitis, 8 episodes, 7 patients) in which blood cultures were uniformly negative for P. aeruginosa. All cases were identified while the patients were receiving
ambulatory care. Five episodes developed while the patients' neutrophil counts were greater than 1 x 10(9) cells/liter. Eight patients had
acute lymphoblastic leukemia, 2 had
acute myeloid leukemia, 2 had
aplastic anemia, 1 had transient
agranulocytosis and 1 had
cyclic neutropenia. There were no solid
tumor patients. Although patients received different
antibiotic combinations, all had resolutions of their lesions without fatal complications. Patients diagnosed as having
cellulitis required a mean of 9.2 days of treatment with intravenous
antibiotics, as compared with 17.8 days for those with
ecthyma gangrenosum (P less than 0.05 by the Wilcoxon test). These observations show that P. aeruginosa skin
infections can develop in the absence of
bacteremia in immunocompromised children.