Trending Clinical Topic: Lyme Disease

Ryan Syrek


June 25, 2021

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Concerns about Lyme disease are on the rise. Interest in updated guidelines for prevention, diagnosis, and treatment (see Infographic below) — along with news about complications and diagnostic testing — resulted in this week's top trending clinical topic.

Lyme disease forecasters are predicting that 2021 may be one for the record books. Last winter was the warmest on record. In various regions with known tick populations, the late spring and early summer weather has been remarkably hot. Warmer, wetter conditions increase tick populations. Combine that with the popularity of outdoor activities after being homebound due to pandemic concerns, and experts say the result may be a boom in tick-borne diseases.

Recently, Lyme disease guidelines were released by the Infectious Diseases Society of America (IDSA), the American Academy of Neurology (AAN), and the American College of Rheumatology (ACR). For prevention, the new guidance recommends repellants, including N,N-diethyl-meta-toluamide (DEET); picaridin; ethyl-3-(N-n-butyl-N-acetyl)aminopropionate (IR3535); oil of lemon eucalyptus; p-menthane-3,8-diol; 2-undecanone; or permethrin. For diagnosis, although submitting ticks for identification is recommended, testing ticks for Borrelia burgdorferi is not. For treatment, oral antibiotic therapy with doxycycline (10-day course), amoxicillin (14-day course), or cefuroxime axetil (14-day course) is recommended for patients with erythema migrans.

The complications of Lyme disease are potentially serious, including cardiac and neurologic involvement. In late 2020, a study found that Lyme neuroborreliosis (LN), a late-stage manifestation of Lyme disease, does not increase the risk of developing serious, long-term psychiatric illness. The large, population-based study did find that a higher percentage of patients received anxiolytic, hypnotic, sedative, and/or antidepressant drugs within the first year after an LN diagnosis; however, after that first year, prescriptions for these medications among the LN group closely matched those of the comparison cohort. Although researchers stress that the study is not the final word on whether neuropsychiatric sequelae may be related to LN, the study "suggests that it is not an overwhelming problem."

Lyme disease remains a challenging diagnosis. Because current tests are based on the development of antibodies in the blood, which may not show up until several weeks after infection, early identification relies heavily on the clinician's experience. Encouragingly, a recent study found that an investigational polymerase chain reaction (PCR) test is able to distinguish between early and late infection. The PCR test detects the presence of a viral gene in Lyme disease–causing bacteria. In an evaluation of 312 samples, significantly fewer copies of the terL gene were found in individuals with early Lyme disease than in those with late Lyme disease, with the fewest copies of terL seen in healthy persons. The hope is that the new phage-based PCR test will allow for early treatment and the prevention of long-term Lyme disease consequences.

With various regions increasingly grappling with Lyme disease and other tick-borne diseases, interest in guidelines as well as potential diagnostic strategies and complications resulted in this week's top trending clinical topic.

Take a quick quiz on key clinical information about Lyme disease.


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