Pediatric mediastinitis as a complication of methicillin-resistant Staphylococcus aureus retropharyngeal abscess.

Objective: To examine changes in the incidence, bacteriology, and complications of retropharyngeal infection (RPI) over an 8-year period.

Design: Retrospective medical record review.

Setting: Tertiary children's hospital.

Patients: The study population comprised 108 patients younger than 18 years old.

Intervention: Medical record review of patients with a discharge diagnosis of RPI (International Classification of Diseases, Ninth Revision code 478.24).

Main Outcome Measures: Cases from June 1997 to May 2001 were compared with those from June 2001 to May 2005 to examine changes in the incidence, bacteriology, and complications of RPI.

Results: The number of RPI cases doubled from 36 to 72 in the final 4 years. In the first 4 years, no isolates of methicillin-resistant Staphylococcus aureus (MRSA) were found, and 1 patient developed mediastinitis. In the last 4 years, 8 of 25 patients (32%) with positive cultures had MRSA isolated, and 7 cases of mediastinitis occurred. Of the 8 children with cultures positive for MRSA, 6 developed mediastinitis. The median age for all children with RPI was 32.5 months (n = 108). The median age for children with MRSA and mediastinitis was 6.5 months (n = 8) and 5.5 months (n = 8), respectively.

Conclusions: An alarming increase in the number of RPI cases occurred over the final 4 years. Methicillin-resistant S aureus is now a significant pathogen in patients with RPI at our institution. Documented local increases in community-associated MRSA infections and universal sensitivity to clindamycin suggest that community-associated MRSA is responsible for the change in bacteriology. A high correlation exists between MRSA infection and mediastinitis. Patients with MRSA infections are younger and may be vulnerable to developing mediastinitis because of immature immune systems. A higher index of suspicion is needed for MRSA, especially in patients younger than 1 year.