Canadian Medical Association

Did you know CMA members have access to skilled medical librarians? Our team of librarians can support you by searching on your behalf, teaching you effective search strategies or training you to use our resources. You’re getting the latest evidence and saving time, so you can focus on what’s important to you.

Summer has arrived—and so have ticks in many areas across Canada. Want to be current on the latest evidence on Lyme disease? Here are some resources selected by Joule’s Ask a Librarian team using a variety of tools offered with CMA membership.

Clinical summary from DynaMed Plus

Access DynaMed Plus online or through the mobile app to get concise overviews and detailed recommendations, medical graphics and images, drug information from Micromedex and more.

Lyme disease is a multisystem inflammatory tick-borne illness caused by spirochetes of the Borrelia burgdorferi sensu lato species complex - commonly found in North America and Europe.

  • 14 days of phenoxymethylpenicillin, amoxicillin, or doxycycline associated with similar time to resolution of erythema migrans (Clin Microbiol Infect 2018 Dec)
  • Lyme neuroborreliosis associated with increased risk of hematologic and nonmelanoma skin cancers but not mortality compared to general population in Denmark (BMJ 2018 May 30)
  • Case series of Lyme carditis and high-degree atrioventricular block (Am J Cardiol 2018 May 1)

Preview (CMA members can access all summaries via this link)

Clinical summary from Essential Evidence Plus

Essential Evidence Plus is an evidence-based point of care tool with access to over 13,000 topics, guidelines, abstracts and summaries. For a synopsis of new evidence reviewed by the Essential Evidence Plus editorial team, subscribe to the POEMs daily newsletter.

Bottom line

  • Look for tick-borne disease in patients with a flu-like illness "out of season" (level of evidence C).
  • An erythema migrans rash in a patient from a Lyme disease endemic region is sufficient reason to begin empiric antibiotic treatment for Lyme disease (level of evidence C).
  • Prevention of Lyme disease and other vector-borne diseases is best accomplished by a combination of avoidance of contact with vectors, use of repellants, appropriate clothing, at least daily whole-body inspections while in risk areas and removal of attached ticks as soon as possible (level of evidence C).
  • Prophylaxis for asymptomatic patients with tick bite only recommended if they meet specific criteria (level evidence B).
  • Preferred oral antibiotics for symptomatic patients are doxycycline, amoxicillin, or cefuroxime axetil (level of evidence B).

Read more via Essential Evidence Plus (CMA members only)

Synopsis of clinical studies in POEMs by Essential Evidence Plus:

POEM: What is the best antibiotic and duration of therapy for early-onset cutaneous Lyme borreliosis?

Bottom line

For patients with early cutaneous Lyme borreliosis (LB), a short course of doxycycline (10 days to 14 days) is as effective as alternative drugs or longer courses. Amoxicillin 500 mg 3 times daily or cefuroxime axetil 500 mg twice daily for 14 days are both reasonable alternatives according to the Centers for Disease Control (CDC) and this analysis. (level of evidence 1a-).  

Reference: Torbahn G, Hofmann H, Rucker G, et al. Efficacy and safety of antibiotic therapy in early cutaneous Lyme borreliosis: A network meta-analysis. JAMA Dermatology 2018;154(11):1292-1303. 

Read full text via POEMs  (CMA members only)


POEM: In children, how accurate is the clinical suspicion for Lyme disease in areas of high prevalence?

Bottom line

For children with suspected Lyme disease but without a classic bull's-eye lesion (erythema migrans of at least 5 cm), check serology rather than rely on your clinical impression. In this study, 12% of the children not suspected of having Lyme disease did have Lyme, and 31% of children thought to have Lyme disease did not have serologic findings either at that time or within 30 days (level of evidence 1b).

Reference: Nigrovic LE, Bennett JE, Balamuth F, et al, for Pedi Lyme Net. Accuracy of clinician suspicion of Lyme disease in the emergency department. Pediatrics 2017;140(6):e20171975. 

Read full text via POEMs (CMA members only)

Further reading

Book Chapters via ClinicalKey (CMA members only):

ClinicalKey drives better care by delivering fast, concise answers, and deep access to evidence whenever, wherever you need it. ClinicalKey includes access to 1,000+ textbooks, 600 full-text journals, images, videos and customizable patient handouts across 30+ medical specialties

Article via CMAJ:

Lyme carditis and atrioventricular block

Douglas Wan and Adrian Baranchuk, CMAJ May 22, 2018 190 (20) E622; DOI:

Clinical Practice Guidelines via CPG Infobase:

CPG Infobase contains approximately 1,200 evidence-based Canadian clinical practice guidelines (CPGs) developed or endorsed by authoritative medical or health organizations in Canada.

There are 8 Canadian Clinical practice guidelines on Lyme disease in CPG Infobase.

Drug Information via CPS online and on the RxTx app (CMA members only):

CPS offers 2000+Canadian product monographs for drugs, vaccines and natural health products that are developed by manufacturers, approved by Health Canada and optimized by CPhA editors

Search “Lyme Disease” in the CPS on the RxTx app to find related monographs and the Drug Choices table which provides dosage, adverse effects, drug interactions and relative cost of treatment for medications.

Need more information or have a more focused clinical question on Lyme disease (or any other clinical topic of interest)? Contact the Ask a Librarian team to request a literature search.

This material is for informational purposes only. It is not intended to be a substitute for professional medical advice and should not be relied on as health or personal advice. The opinions stated by the authors are made in a personal capacity and do not necessarily reflect those of the Canadian Medical Association and its subsidiaries including Joule.  Feel passionate about physician-led innovation? Please connect with us at

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