Lyme disease and Bell's palsy: an epidemiological study of diagnosis and risk in England.

BACKGROUND: Lyme disease is caused by a tick-borne spirochaete of the Borrelia species. It is associated with facial palsy, is increasingly common in England, and may be misdiagnosed as Bell's palsy. AIM: To produce an accurate map of Lyme disease diagnosis in England and to identify patients at risk of developing associated facial nerve palsy, to enable prevention, early diagnosis, and effective treatment. DESIGN AND SETTING: Hospital episode statistics (HES) data in England from the Health and Social Care Information Centre were interrogated from April 2011 to March 2015 for International Classification of Diseases 10th revision (ICD-10) codes A69.2 (Lyme disease) and G51.0 (Bell's palsy) in isolation, and as a combination. METHOD: Patients' age, sex, postcode, month of diagnosis, and socioeconomic groups as defined according to the English Indices of Deprivation (2004) were also collected. RESULTS: Lyme disease hospital diagnosis increased by 42% per year from 2011 to 2015 in England. Higher incidence areas, largely rural, were mapped. A trend towards socioeconomic privilege and the months of July to September was observed. Facial palsy in combination with Lyme disease is also increasing, particularly in younger patients, with a mean age of 41.7 years, compared with 59.6 years for Bell's palsy and 45.9 years for Lyme disease (P = 0.05, analysis of variance [ANOVA]). CONCLUSION: Healthcare practitioners should have a high index of suspicion for Lyme disease following travel in the areas shown, particularly in the summer months. The authors suggest that patients presenting with facial palsy should be tested for Lyme disease.