Acute mastoiditis in Norway: no evidence for an increase.

Objective: In a large Norwegian newspaper in November 2005, an otolaryngologist at Rikshospitalet claimed that the increasing number of children hospitalized for acute mastoiditis was worrying and questioned the restrictive use of antibiotics in Norway. Based on latter he recommended that all children below age 2 with symptoms of uncomplicated acute otitis media should receive antibiotics. Our purpose was to incidence variation and characteristics of acute mastoiditis in children.

Methods: Registry based study with complete data on hospitalization for acute mastoiditis and cortical mastoidectomy in Norway during 1999-2005.

Results: Three hundred and ninety-nine Norwegian children aged 0-16 years were included. The incidence of acute mastoiditis in children below 2 ranged from 13.5 to 16.8 per 100,000 during the study period. Corresponding numbers for children 2-16 years were 4.3-7.1 per 100,000 children. No incidence increase was found during the study period. Age-specific incidence revealed a peak during the second and third year of life, and acute mastoiditis was most common in boys. Cortical mastoidectomy was equally common in the young and older age group, 22% received surgery. For children aged 2 and above, significantly fewer children were hospitalized for acute mastoiditis media during the period July, August and September.

Conclusion: Despite the introduction of restrictive Norwegian guidelines for antibiotic treatment of acute otitis media in children aged 1 year and above, our data did not give evidence for an increase in acute mastoiditis. Except for the high incidence of acute mastoiditis in young children, hospitalization characteristics were remarkably similar in children below and above 2 years.