Acute mastoiditis in children aged 0-16 years--a national study of 678 cases in Sweden comparing different age groups.

Objective: To compare the characteristics of acute mastoiditis in children in different age groups in order to identify risk groups and risk factors for acute mastoiditis.

Methods: Records for all children aged 0-16 years treated for acute mastoiditis during 1993-2007 at 33 Ear, Nose and Throat departments in Sweden were reviewed retrospectively according to defined criteria for acute mastoiditis.

Results: A total of 678 cases fulfilled the inclusion criteria. Acute mastoiditis was most common in children younger than two years of age and this group was characterized by less prior history of other diseases and ear diseases, fewer visits to health care centers and less antibiotic treatment before admission, shorter duration of symptoms before admission, hospitalization for fewer days and lower frequency of complications and mastoidectomies. These children also showed a higher incidence of clinical findings, increased inflammatory markers such as fever and heightened counts of C-reactive protein and white blood cells compared with older children. They also tested positive for significantly more samples of Streptococcus pneumoniae while the older children more often exhibited growth of Streptococcus pyogenes or Pseudomonas aeruginosa or no microbial growth.

Conclusions: The characteristics of pediatric acute mastoiditis differed significantly between age groups. Acute mastoiditis was most common in children younger than two years of age. They showed more rapid progress of symptoms and more distinct signs of acute mastoiditis. This is probably the reason why parents rapidly seek medical care for small children and hospital treatment thus starts earlier in the youngest children, which may in turn explain the excellent outcome. This study showed that younger children have neither more severe acute mastoiditis nor more complications than older ones. The differences between age groups suggest that there are distinctions in the pathophysiology behind the onset and course of acute mastoiditis in younger and older children.