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.