Differential diagnosis 

    • co-infection

    • babesiosis

    • human granulocytic anaplasmosis (“ehrlichiosis”)

  • other Borrelial infection

    • southern tick-associated rash illness (STARI) (Borrelia lonestari )

    • Borrelia miyamotoi


  • hospitalization advised for symptomatic Lyme carditis

  • usual antibiotic treatment for adults (IDSA guidelines) 

    • early Lyme disease
      • for EM without complications, any of
        • doxycycline 100 mg orally twice daily for non-pregnant patients ≥ 8 years old for 14 days 

        • amoxicillin 500 mg orally 3 times daily for 14 days 

        • cefuroxime axetil 500 mg orally twice daily for 14 days

    • for early neurologic Lyme disease

      • ceftriaxone 2 g IV once daily for 14 days 

      • alternatives if normal renal function
        • cefotaxime 2 g IV every 8 hours
penicillin G 18-24 million units/day in 6 divided doses 
doxycycline 200-400 mg/day orally in 2 divided doses if unable to tolerate beta-lactam antibiotics
    • for seventh cranial nerve palsy
      • if both clinical and laboratory evidence of CNS involvement, use same for early neurologic Lyme disease 

      • if CSF exam normal/unnecessary, use 14-day regimen for EM
    • for Lyme carditis, treat for 14-21 days with
      • ceftriaxone 2 g IV once daily (inpatients)

      • oral regimen as for EM (outpatients or to complete therapy after hospitalization)

    • late Lyme disease
      • for Lyme arthritis without neurologic involvement, treat for 28 days using EM dosing with doxycycline or amoxicillin or cefuroxime 

      • for late neurologic Lyme disease, treat for 2 to 4 weeks with antibiotics used for early neurologic Lyme disease 

      • for Lyme arthritis with neurologic involvement, treat with antibiotics and duration as for late neurologic Lyme disease

      • for acrodermatitis chronic atrophicans, treat for 21 days with antibiotics used for EM 

    • avoid doxycycline if pregnant or lactating 

  • other treatments

    • temporary pacemaker (if advanced heart block)

    • arthroscopic synovectomy (if persistent synovitis)

  • alternative therapies

    • Bismacine (Chromacine) NOT recommended

    • no evidence to support alternative therapies 


  • test of cure should not be performed (seroreactivity can persist for years)


  • arthritis

  • carditis

  • neurologic

    • facial nerve paly

    • meningitis

    • encephalomyelitis

    • radiculoneuropathies


  • untreated EM typically resolves in 3-4 weeks

  • excellent long-term prognosis with early antibiotic treatment

  • repeat episodes of EM more likely to be re-infection than relapse 

  • post-Lyme disease syndromes

    • no evidence for existence of symptomatic chronic B. burgdorferi infection after recommended treatment regimen 

    • antibiotic therapy not proven to be useful and not recommended for patients with chronic (≥ 6 months) subjective symptoms after recommended treatment


  • tick avoidance measures include

    • decreased time in tick-infested habitats

    • light-colored clothing with long pants tucked into socks and long-sleeve shirts

    • tick repellents and use of permethrin-treated clothing 

  • bite care

    • preferred method of tick removal is using forceps or tweezers grasping tick as close to skin surface as possible and pulling upward with steady pressure

    • disinfect bite site and save tick for identification

    • avoid use of physical substances (such as petroleum jelly) or heat (ineffective for tick removal)

  • antibiotic prophylaxis following tick-bite (IDSA guidelines)

    • routine prophylaxis not recommended 

    • consider single-dose doxycycline (200 mg for adults, 4 mg/kg (maximum 200 mg) for children ≥ 8 years old) if
      • tick adherent for ≥ 36 hours 

      • area endemic for B. burgdorferi

      • < 72 hours after bite

    • single-dose doxycycline 200 mg within 72 hours of Ixodes scapularis tick bite may be effective

Alan Drabkin, MD, is a senior clinical writer for DynaMed, a database of comprehensive updated summaries covering more than 3,200 clinical topics, and assistant clinical professor of population medicine at Harvard Medical School.

Continue Reading