Lyme disease: clinical diagnosis and treatment

Lyme disease is an emerging zoonotic infection in Canada. As the Ixodes tick expands its range, more Canadians will be exposed to Borrelia burgdorferi, the bacterium that causes Lyme disease.

To review the clinical diagnosis and treatment of Lyme disease for front-line clinicians.

A literature search using PubMed and restricted to articles published in English between 1977 and 2014.

Individuals in Lyme-endemic areas are at greatest risk, but not all tick bites transmit Lyme disease. The diagnosis is predominantly clinical. Patients with Lyme disease may present with early disease that is characterized by a "bull's eye rash", fever and myalgias or with early disseminated disease that can manifest with arthralgias, cardiac conduction abnormalities or neurologic symptoms. Late Lyme disease in North America typically manifests with oligoarticular arthritis but can present with a subacute encephalopathy. Antibiotic treatment is effective against Lyme disease and works best when given early in the infection. Prophylaxis with doxycyline may be indicated in certain circumstances. While a minority of patients may have persistent symptoms, evidence does not demonstrate that prolonged courses of antibiotics improve outcome.

Clinicians need to be aware of the signs and symptoms of Lyme disease. Knowing the regions where Borrelia infection is endemic in North America is important for recognizing patients at risk and informing the need for treatment.