Lyme disease is a tick-borne bacterial infection caused by Borrelia burgdorferi, transmitted via hard-backed Ixodes ticks. In the United States, Lyme disease is predominant in the northeast and upper midwestern section. The incidence rate is approximately 40 per 100,000 people where Lyme disease is common, occurring during late spring, summer, and early fall. Lyme disease is tested via a 2-step approach to first identify serum antibodies to B. burgdorferi followed by a Western blot to confirm findings for both IgM and IgG antibodies. Lyme disease at the early stage is most commonly presented as a rash (erythema migrans) that occurs one to two weeks later at the site of tick bite, which can be accompanied by a low-grade fever. Disease progression to late-stage Lyme disease can lead to muscle pain, neurologic, and cardiac complications presenting as a number of symptoms (e.g., malaise, fever, muscle pain, chest pain, palpitations, dyspnea, arthritis). The central nervous system may also be involved (e.g., encephalopathy, meningitis, cranial nerve neuropathy). A vaccine is currently not available for prevention of Lyme disease and mainly focuses on tick repellent and removal. The early cases of Lyme disease respond promptly to oral antibiotic therapy. Yet, some patients may require additional treatment or experience post-treatment Lyme disease with persistent systems untreatable with antibiotics. [1], [2], [3], [4]
The Infectious Disease Society of America (IDSA) has published a comprehensive 2020 guidelines on the management of Lyme disease, the tick-borne infection. Upon removal of an identified high-risk tick bite (identified Ixodes ssp. Vector species; occurred in a highly endemic area; attached for > 36 hours), antibiotic prophylaxis of oral doxycycline within 72 hours of removal is recommended over observation. Doxycycline is dosed at 200 mg single oral for adults and 4.4 mg/kg (up to a max 200 mg) for children. Patients with equivocal or low risk (or cannot be identified as high risk with certainty) are recommended to undergo wait and watch method. [5]
Patients with confirmed erythema migrans are recommended to receive oral antibiotics with doxycycline, amoxicillin, or cefuroxime axetil as the first-line or azithromycin as the second-line with treatment lasting either 10 days for doxycycline, 14 days for amoxicillin or cefuroxime, or 5-10 days (7 days preferred in the United States) for azithromycin. [5]
Patients with acute neurological manifestations of Lyme disease without parenchymal involvement of the brain or spinal cord are recommended to receive intravenous (IV) ceftriaxone, cefotaxime, penicillin G, or oral doxycycline for 14 to 21 days, although oral may be considered based on patient factors and tolerance. Lyme disease associated with parenchymal involvement of brain or spinal cord should receive IV over oral antibiotics. [5]
No recommendations are made regarding corticosteroid use as an adjunct to antibiotics if facial nerve palsy is involved. Patients with severe cardiac complications due to Lyme disease (e.g., arrhythmia, myopericarditis) are recommended to be hospitalized with ECG monitoring. Lyme carditis may be treated with oral antibiotics using doxycycline, amoxicillin, cefuroxime axetil, or azithromycin in the outpatient setting; or IV ceftriaxone if hospitalized (which can be switched to oral once clinical improvement is observed) for 14 to 21 days. Patients with diagnosis of Lyme arthritis are recommended to receive oral antibiotics for 28 days with a follow-up of 2- to 4-week course of IV ceftriaxone should there be no or minimal improvement. Patients diagnosed with borrelial lymphocytoma are recommended to receive oral antibiotics for 14 days. Patients with acrodermatitis chronia atrophicans are recommended to receive oral antibiotics for 21 to 28 days. [5]
If a patient presents with certain acute disorders related to Lyme disease (e.g., meningitis, painful radiculoneuritis, spinal cord inflammation, etc.), then testing for Lyme disease is recommended. Patients with certain psychiatric or neurological conditions (e.g., Parkinson’s disease, dementia) are recommended against routine testing. [5]