Clinical outcome parameters for necrotizing otitis externa.

Objective: To investigate the duration of time elapsed between the onset of symptoms for necrotizing external otitis (NEO) and admission to hospital that may play a role in patient outcome.

Study Design: Retrospective case review.

Setting: Tertiary referral center.

Patients: Fourteen consecutive male patients with NEO with no improvement from the previous course of antibiotherapy and with findings of osteomyelitis on temporal bone CT, MRI, and positive detection of Tc-99m methylene diphosphonate on temporal bone, admitted as inpatients between 2008 and 2012.

Intervention(s): Medical treatment of NEO and surgical debridement.

Main Outcome Measure(s): Patients were divided into 2 groups according to median time elapsed between onset of symptoms and hospitalization (<30 d or >30 d). HbA1c, fasting blood sugar, erythrocyte sedimentation rate, C-reactive protein, pain intensity, radiologic grade, improvement since diagnosis, and total time to cure were compared according to the groups. The relationships between the laboratory data were analyzed to determine the parameters associated with time to recovery.

Results: Otalgia was significantly worse in patients who were admitted to hospital greater than 30 days after symptom onset (Mann-Whitney U test, p < 0.002). Blood glucose increased related to delayed admission time (p < 0.001). CRP results were independently elevated from the admission time (p < 0.112). There was a statistically significant difference between groups according to ESR levels and recovery time (Mann-Whitney U test, p < 0.004 and p < 0.01). There was a positive correlation between HbA1c levels and recovery time in Group 1 and between ESR levels and recovery time in Group 2 (r = 0.872, p = 0.044; r = 0.630, p = 0.039).

Conclusion: Clinical, laboratory, and outcome data worsen later than 30 days in NEO.