RESUMO
BACKGROUND: Etiologies for Bell's palsy include herpes viruses and Lyme disease, with highest incidence in the colder and warmer months, respectively. In New Jersey, a Lyme-endemic area, the months with the most Lyme disease (80% of cases) are May through October ("Lyme months"). OBJECTIVE: Our aim was to determine whether positive tests for Lyme disease and visits are greater in the Lyme months than the rest of the year for patients with Bell's palsy in New Jersey emergency departments (EDs). METHODS: We conducted a retrospective chart review from two New Jersey suburban EDs with consecutive patients from February 1, 2013 to January 31, 2018.We identified patients having Bell's palsy using the emergency physician diagnosis. We tabulated positive Lyme tests and visits for Bell's palsy by month of year. We calculated the ratio of positive tests and visits between the Lyme months and the rest of the year along with 95% confidence intervals (CIs). RESULTS: There were 442 visits for Bell's palsy, 359 (81%) of these patients were tested for Lyme disease and 57 (16%) of the tests were positive. The Lyme months had 7.1 (95% CI 3.5-14.4) times more positive tests and 1.3 (95% CI 1.1-1.4) times more Bell's palsy visits than the rest of the year. Both measures peaked in July. CONCLUSIONS: In a Lyme-endemic area, positive Lyme tests and ED visits for Bell's palsy are greatest in the Lyme months, peaking in July. This finding can help guide testing and treatment for patients in the ED with Bell's palsy during various months of the year.