Exploring theories for the exponential 16-year rise in incidence of necrotising otitis externa in England

Background Necrotising otitis externa is a severe, life-threatening infection. Epidemiological data demonstrate a dramatic rise in reported cases in England from 2002 to 2017. The reasons for this remain elusive. Methods A quantitative descriptive study was undertaken using epidemiological data from the Hospital Episode Statistics database. Cases from 2002 to 2017 were compiled and analysed. Four potential theories were explored to explain the rise in incidence. Results Within the 16-year period, 7327 necrotising otitis externa cases were reported. Annual necrotising otitis externa incidence increased 1142 per cent within the 16-year period, from 123 recorded cases in 2002 to 1405 cases in 2017. This correlates with an increasing prevalence of diabetes, an ageing population and likely increased physician awareness of necrotising otitis externa. There is insufficient evidence to support antibiotic resistance as a significant associated factor. Conclusion Correlation does not imply causation. It is likely that a combination of factors is contributing to the rise in necrotising otitis externa incidence, including increased physician recognition, diagnosis and accurate clinical coding.