title: Bacteriology in relation to clinical findings and treatment of acute mastoiditis in children.
abstract: OBJECTIVE
  We assessed clinical, radiological, laboratory and microbiological findings in children with acute mastoiditis in order to improve the diagnostics and treatment of these patients. We also investigated whether different pathogens cause different clinical findings of mastoiditis.
  
  
  METHODS
  A retrospective review of the medical records of all children aged 0-16 years treated as in-ward patients for acute mastoiditis at Helsinki University Central Hospital, Department of Otorhinolaryngology, between 2003 and 2012.
  
  
  RESULTS
  Fifty-six patients met the inclusion criteria. The incidence of mastoiditis was 1.88/100000/year. The most common pathogens were Streptococcus pneumoniae (38%), Streptococcus pyogenes (11%) and Pseudomonas aeruginosa (11%). Of S. pneumoniae, 48% had reduced susceptibility (intermediate or resistant) for the common antimicrobials; this was clearly overrepresented relative to the background population (p<0.001). Otalgia and retroauricular symptoms were common in the patients with S. pneumoniae. Otorrhoea was less common (p=0.03) in these patients relative to the other pathogens. Patients with S. pneumoniae had more destruction of the mastoid septa (p=0.05) than patients with any of the other pathogens. Mastoidectomy was performed in 34% of all cases, it was most common (60%) in the patients with S. pneumoniae with reduced susceptibility. The patients with S. pyogenes had less otalgia and seemed to have less retroauricular symptoms relative to other pathogens. P. aeruginosa especially affected children with tympanostomy tubes, caused otorrhoea in all patients and caused a milder form of disease with less retroauricular swelling (p=0.04) than the other pathogens, and there was no need for mastoidectomies. The younger children (<2 years) had less otorrhoea and more retroauricular symptoms of infection than the older patients. No significant differences emerged in outcome of the patient groups.
  
  
  CONCLUSIONS
  The clinical findings of acute mastoiditis differ according to the causative pathogen. S. pneumoniae, especially strains with reduced susceptibility, causes severe symptoms and leads to mastoidectomy more often than the other pathogens. S. pyogenes causes less otalgia than the other pathogens. P. aeruginosa particularly affects children with tympanostomy tubes and causes a less aggressive form of disease.
authors.affiliation: Department of Otorhinolaryngology, Helsinki University Central Hospital, Haartmaninkatu 4E, PO Box 220, FI-00029 HUS, Helsinki, Finland; Department of Allergy, Helsinki University Central Hospital, PO Box 160, FI-00029 HUS, Helsinki, Finland; University of Helsinki, Helsinki, Finland. Electronic address: anu.laulajainen-hongisto@hus.fi.
authors.forename: Anu
authors.initials: A
authors.lastname: Laulajainen-Hongisto
authors.affiliation: Department of Radiology, HUS Medical Imaging Centre, Helsinki University Central Hospital, Haartmaninkatu 4, PO Box 340, FI-00029 HUS, Helsinki, Finland; University of Helsinki, Helsinki, Finland.
authors.forename: Riste
authors.initials: R
authors.lastname: Saat
authors.affiliation: Department of Otorhinolaryngology, Helsinki University Central Hospital, Haartmaninkatu 4E, PO Box 220, FI-00029 HUS, Helsinki, Finland; University of Helsinki, Helsinki, Finland.
authors.forename: Laura
authors.initials: L
authors.lastname: Lempinen
authors.affiliation: Department of Radiology, HUS Medical Imaging Centre, Helsinki University Central Hospital, Haartmaninkatu 4, PO Box 340, FI-00029 HUS, Helsinki, Finland; University of Helsinki, Helsinki, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Markkola
authors.affiliation: Department of Otorhinolaryngology, Helsinki University Central Hospital, Haartmaninkatu 4E, PO Box 220, FI-00029 HUS, Helsinki, Finland; University of Helsinki, Helsinki, Finland.
authors.forename: Antti A
authors.initials: AA
authors.lastname: Aarnisalo
authors.affiliation: Department of Otorhinolaryngology, Helsinki University Central Hospital, Haartmaninkatu 4E, PO Box 220, FI-00029 HUS, Helsinki, Finland; University of Helsinki, Helsinki, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Jero
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D004433:Earache / Q000382:microbiology; D004487:Edema / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008416:Mastoid / Q000601:surgery; D008417:Mastoiditis / Q000175:diagnosis / Q000188:drug therapy* / Q000382:microbiology*; D008876:Middle Ear Ventilation; D011552:Pseudomonas Infections / Q000175:diagnosis / Q000188:drug therapy*; D011550:Pseudomonas aeruginosa; D012189:Retrospective Studies; D013290:Streptococcal Infections / Q000175:diagnosis / Q000188:drug therapy*; D013296:Streptococcus pneumoniae; D013297:Streptococcus pyogenes
chemical_list: D000900:Anti-Bacterial Agents
keywords: Bacterial resistance; Bacteriology; Complications; Mastoidectomy; Mastoiditis; Pediatric