To The Editors:
We present the novel case of a toddler with Pseudomonas aeruginosa axillary lymphadenitis without predisposing factors. A 13-month-old male toddler developed fever to 102.4°F and right axillary lymphadenitis. Physical examination was notable only for a tender, erythematous, fluctuant right axillary lymph node measuring 1 cm by 1.5 cm. Laboratory evaluation revealed a white blood cell count of 18,000/mm3 with 1% bands, 28% neutrophils, 66% lymphocytes, and 5% monocytes; hemoglobin 12.1 g/dL, hematocrit 36.7%, and platelet count 199,000/mm3. Blood culture was negative. The lymph node was incised and drained in the operating room, yielding 5 mL of pus. Therapy was begun with a first-generation cephalosporin. Culture of the lymph node pus grew P. aeruginosa. Empiric therapy was discontinued and the child completed a 14-day course of oral ciprofloxacin with complete resolution of the lymphadenitis.
Because of this unusual culture result, the child was referred to the Infectious Diseases service for evaluation. The wound was healing well. There was no history of trauma and the child had never been in a hot tub. The child had not had any skin, soft tissue, or lymph node infections in the past. He had never been admitted to the hospital before. He was well grown and developmentally appropriate. There was no family history of similar infections or of early death or immunocompromise.
Further laboratory investigation for immune deficiency and other predisposing conditions was performed. Repeat white blood cell count was 15,200/mm3 with 30% neutrophils, 68% lymphocytes, 1% monocytes, and 1% eosinophils; hemoglobin 12.1 mg/dL, hematocrit 36.5%, and platelet count 465,000/mm3. Erythrocyte sedimentation rate, serum electrolyte values, and serum hepatic transaminases were normal. Serum IgG was 417 mg/dL (normal values, 118–965 mg/dL), serum IgA was 24.5 mg/dL (14–84 mg/dL), and serum IgM was 54 mg/dL (31–181 mg/dL). Flow cytometry demonstrated 49% (29–68%) T-helper lymphocytes. Total hemolytic complement was 43 U/mL (26–58 U/mL). An assay for chronic granulomatous disease demonstrated that the percentage of oxidation-positive neutrophils at 48 hours was 96% (normal >83%). The wound healed well and the child has been asymptomatic for almost 3 years.
Lymphadenitis, as reported in our patient, is a novel manifestation of infection with P. aeruginosa. Common causes of axillary lymphadenitis in the pediatric age group include cat-scratch disease, staphylococcal or streptococcal infections, and atypical mycobacterial infections.1 Less common entities include tularemia and brucellosis. A literature search revealed a single 1969 case report (in Slovak) of a 15-year-old with P. aeruginosa cervical lymphadenitis2 as the only other documented case of pseudomonal lymphadenitis.
We document the first reported case of P. aeruginosa axillary lymphadenitis. In children with any unusual manifestation of infection (eg, infection in an anatomic location not usually affected by a particular pathogen), underlying immunodeficiency should be sought.3 This toddler did not have any apparent predisposing condition and extensive evaluation was negative.
The authors thank Drs. Howard Brauer, Lawrence Ettinger, and Philip Therrien for assistance with the care of this child and Jeannine Creazzo, Elizabeth Herron, Jennifer Ross, and Linda Scott of the Saint Peter’s University Hospital Library for assistance with review of literature.
Swetha Geetha Pinninti, MD
The Children’s Hospital at
Saint Peter’s University Hospital
New Brunswick, NJ
Robert W. Tolan, Jr, MD
Division of Allergy, Immunology and
The Children’s Hospital at Saint Peter’s
New Brunswick, NJ
Drexel University College of Medicine
1. Karadeniz C, Oguz A, Ezer U, Oztürk G, Dursun A. The etiology of peripheral lymphadenopathy in children. Pediatr Hematol Oncol
2. Galanda V, Buchanec J. [Suppurative lymphadenitis of the cervical lymph nodes caused by Pseudomonas aeruginosa in a 15-year-old boy.] Cesk Pediatr
3. Tolan RW Jr. Infections in the immunocompromised host. Emedicine Online Textbooks, Emedicine.com
[serial online]. 2006. Available at: http://www.emedicine.com/ped/topic3096.htm
. Accessed May 31, 2008.