In a recently released article in Pediatrics, Dr. Guez-Barber and colleagues present a fascinating study that aims to describe the clinical course of patients ages 1-18 years presenting with unilateral acute facial palsy, to define clinical factors that might distinguish Bell’s palsy from Lyme-related facial palsy, and to compare whether receipt of steroids was associated with full recovery of a facial palsy (10.1542/peds.2021-053992). I don’t practice in a Lyme-endemic region, so initially I was unsure how relevant this article would be for me, but I have concluded it is truly helpful, and I hope you will agree. The authors examined records from a 5-year period (7/1/13-6/30/18) from their large health care network in southeastern Pennsylvania and New Jersey; they identified 306 eligible patients with a median age of 10.3 years who had acute-onset unilateral peripheral facial palsy. Most had either Bell’s palsy (209/306) or Lyme-related facial palsy (82/306); just 15 had other diagnoses.
Their large health care network has about 750,000 primary care, 88,000 emergency room and 31,000 urgent care visits annually. Based on the number of cases included from this large dataset, clearly acute unilateral facial palsy is infrequent and therefore trying to discern the appropriate workup can be challenging. For example, does every child need cranial imaging (or a lumbar puncture), and if not every child, then which child? The results of this particular study will likely convince you that the answer to this question is, “no – neuroimaging is not needed for acute isolated unilateral facial palsy.” The authors report that the presence or absence of prodromal symptoms, defined as at least 3 of 5 reported symptoms (i.e. fever, headache, malaise, arthralgias, and myalgias) in the preceding 6 weeks, and seasonality, defined as presentation between June and November versus other times of the year, were really the “give aways” that allow you to differentiate between Lyme and Bell’s palsies. Children with Lyme-related facial palsy presented mainly between June and December and more than half had a systemic prodrome, while those with Bell’s palsy presented throughout the year, and a systemic prodrome was rare. Appropriate titers for Lyme disease were obtained and used to make that particular diagnosis. There were two children who were later diagnosed with malignancy (one with medulloblastoma and another with leukemia). These children had additional signs and symptoms (additional neurologic symptoms with medulloblastoma; fever and weight loss with leukemia) that developed within a very short period, leading to evaluation and subsequent diagnosis of cancer.
There is so much more to learn in this article, and I don’t want to spoil it all for you. Is a history of tick bite or erythema migrans, the characteristic rash of Lyme disease, also diagnostically critical? Did steroids appear to hasten resolution of all, some, or any patients? There are additional clinical tips and “take homes” awaiting you in this article. Most notably it is affirming to learn that there still is an important role for a good history to play, even more than ordering expensive imaging tests in the ability to diagnose different types of facial palsies. Let us know if you feel similarly after linking to this study and learning more!