Objective: The objective of this study was to assess clinical reports and bacteriological changes over a 25-y period in children with acute mastoiditis.
Methods: The medical files of all children with a discharge diagnosis of mastoiditis, hospitalized in a tertiary pediatric medical center over a 2-y period (2008-2009), were reviewed and compared to previously published data from the same center for the y 1983-1985, 1993-1995, and 2003-2007.
Results: One hundred and thirty-four children (143 episodes) with acute mastoiditis were identified during 2008-2009; 81% had fever, 95% auricular displacement, and 80% post-auricular swelling. Forty-nine children were diagnosed with acute otitis media and had been treated with antibiotics prior to hospitalization. However, 22% showed no clinical symptoms preceding ear protrusion. Cultures grew Streptococcus pneumoniae in 32%, Streptococcus pyogenes in 20%, Pseudomonas aeruginosa in 13%, and Haemophilus influenzae in 10% of cases. From 1990 to 2005, the incidence of S. pyogenes isolation increased from approximately 5% to 20%. During this period, the number of cases increased from 8-20 to 67 per y.
Conclusions: S. pyogenes has emerged as a significant pathogen. We found that acute mastoiditis may appear without preceding symptoms in approximately 22% of cases.