Lyme disease

(Redirected from Borrelia burgdorferi)


National Lyme disease risk map with 4 categories of risk.
Ixodes tick
  • Caused by spirochete Borrelia burgdorferi
    • Typically carried on Ixodes scapularis aka Deer tick
    • The spirochete Borrelia mayonii has been a new strain implicated in cases in the midwest[1]
  • Endemic to the northeastern US
  • Peak time of infection is May to August
  • Stages: Early localized infection, early disseminated, and late disseminated

Clinical Features

"Classic" bull's-eye rash (i.e. erythema migrans) found in 70%-80% of cases[2]

3 Distinct Stages - Not all patients suffer all stages, and stages may overlap with remissions between stages

Early Localized Infection (7-14 Days)

  • Erythema Chronicum Migrans: Occurs at site of tick bite, beginning with red macule that expands outward. Starts 3-30 days after bite and occurs in 70-80% of cases
  • Erythema migrans rash more often without central clearing
  • Fatigue, low grade fever, migrating arthralgia, lymphadenopathy, headache, nausea/vomiting, abdominal pain

Early Disseminated Infection (Days to Weeks)

Late Disseminated Infection (Months to Years)

  • Arthritis: Monarticularule outligoarticular asymmetric arthritis (large joints-commonly knee)
    • Brief episodes separated with complete remission
    • Migratory pattern may occur
  • Nervous System: Subtle encephalopathy, fatigue, polyneuropathy

Differential Diagnosis


Algorithm for Polyarticular arthralgia

Tick Borne Illnesses


  • ELISA if positive obtain confirmatory Western blot
  • PCR
  • Cultures, serologies
  • LP with lymphocytic pleocytosis, elevated protein, normal glucose, + spirochete antibody, paired serum/CSF serologic tests,PCR
    • Must be performed in patients with neuro findings (facial nerve palsy, meningoencephalitis, etc)
    • CNS Lyme disease will be treated with ceftriaxone
  • Arthrocentesis, serologic testing of fluid


No risk when duration of attachment <24 hrs


  • Adult: Doxycycline 200mg PO x1
  • Child >8: 4mg/kg up to 200mg PO x1
  • Give if all of the following are met:
    • Tick is adult/nymphal I. scapularis
    • Tick was attached >36 hours based on degree of engorgement or exposure time
    • Prophylaxis can be given within 72 hrs after time tick was removed
    • Local rate of infection in ticks >20%
    • Doxycycline is not contraindicated
  • Old vaccine has little to no efficacy after 1 year

Early Localized Infection

  • Treat before serologic testing if endemic area if + erythema migrans rash
  • Jarisch-Herxheimer like reaction can occur in first 24 hrs of treatment (fevers, chills, myalgia, tachycardia)

Early Disemminated

Lyme Meningitis

Cardiac Disease




  • Early Disease
  • Late Disease: If chronic neurologic/arthritic manifestations may be able to manage as outpatient
  • Follow up with primary care, rheum, ID


  • Lyme carditis-cardiac monitoring
  • Prominent neurologic symptoms for IV antibiotics and further care

See Also

External Links


  1. Pritt BS, Mead PS, Johnson DKH, et al.Identification of a novel pathogenic Borrelia species causing Lyme borreliosis with unusually high spirochaetaemia: a descriptive study. Lancet Infectious Disease. Published Online: 05 February 2016.
  2. Signs and Symptoms of Lyme Disease, CDC, page last reviewed: June 16, 2015.
  3. 3.0 3.1 3.2 Clinical Practice Guidelines by the Infectious Diseases Society of America, American Academy of Neurology, and American College of Rheumatology 2020 Guidelines for the Prevention, Diagnosis, and Treatment of Lyme Disease. Lantos et al. Neurology Feb 2021, 96 (6) 262-273; DOI: 10.1212/WNL.0000000000011151