Infants under the age of six months with acute mastoiditis. A descriptive study of 15 years in Sweden.

OBJECTIVE: To investigate the occurrence, clinical signs and outcome of acute mastoiditis in infants under the age of 6 months in Sweden between the years 1993-2007. METHODS: All ENT departments in Sweden reported children 0-5 months treated for acute mastoiditis 1993-2007 and all records were reviewed. The clinical course and various characteristics were recorded. RESULTS: Seventeen young infants with acute mastoiditis were identified. Three patients had suffered acute otitis media earlier, otherwise the children were previously healthy. Preceding the episode of acute mastoiditis, the children had an upper respiratory tract infection or fever for seven days in mean (median three days) and the mean number of days with ear-symptoms was three days (median two days). Three patients were treated with antibiotics prior to admittance. Almost all children presented with clear retroauricular signs with protruding ear and redness behind the ear. The children were hospitalised for six days (mean and median). Eight patients (47%) suffered from a subperiosteal abscess. All but one patient underwent surgery: myringotomy (13); incision or punction of the mastoid (5); mastoidectomy (3). Streptococcus pneumoniae was the most frequent bacterium identified in cultures. No intracranial complications or other severe complications were found. CONCLUSION: Acute mastoiditis is extremely rare in infants under the age of 6 months. The patients in this study did not have any predisposing diseases. An upper respiratory tract infection had preceded the episode of acute mastoiditis for some time in the majority of cases, but the time from first ear symptoms to hospitalization was very short. Acute mastoiditis is a potentially life-threatening disease, but the timely administration of intravenous antibiotics and surgical intervention prevented the occurrence of severe complications in these young infants.

National assessment of validity of coding of acute mastoiditis: a standardised reassessment of 1966 records.

OBJECTIVES: To investigate the internal validity of the diagnosis code used at discharge after treatment of acute mastoiditis. DESIGN: Retrospective national re-evaluation study of patient records 1993-2007 and make comparison with the original ICD codes. SETTING: All ENT departments at university hospitals and one large county hospital department in Sweden. PARTICIPANTS: A total of 1966 records were reviewed for patients with ICD codes for in-patient treatment of acute (529), chronic (44) and unspecified mastoiditis (21) and acute otitis media (1372). MAIN OUTCOME MEASURES: ICD codes were reviewed by the authors with a defined protocol for the clinical diagnosis of acute mastoiditis. Those not satisfying the diagnosis were given an alternative diagnosis. RESULTS: Of 529 records with ICD coding for acute mastoiditis, 397 (75%) were found to meet the definition of acute mastoiditis used in this study, while 18% were not diagnosed as having any type of mastoiditis after review. Review of the in-patients treated for acute media otitis identified an additional 60 cases fulfilling the definition of acute mastoiditis. Overdiagnosis was common, and many patients with a diagnostic code indicating acute mastoiditis had been treated for external otitis or otorrhoea with transmyringeal drainage. CONCLUSIONS: The internal validity of the diagnosis acute mastoiditis is dependent on the use of standardised, well-defined criteria. Reliability of diagnosis is fundamental for the comparison of results from different studies. Inadequate reliability in the diagnosis of acute mastoiditis also affects calculations of incidence rates and statistical power and may also affect the conclusions drawn from the results.