II. Epidemiology
-
Incidence
- Most common tick borne disease in North America
- Cases in U.S. in 1994: 13,000
- Cases in U.S. in 1999: 16,000
- Cases in U.S. in 2006: 20,000
- Cases in U.S. in 2014: 19,985
- Annual Incidence in endemic areas: 0.5%
- Peak occurrence in North America: May to August
- Demographics
- Gender: Much more common in males
- Age: Bimodal peak distribution (ages 5-9 and 55-59 years old)
- Geographic areas involved
- Worldwide cases have occurred in Canada, Europe, Asia
- U.S. cases clustered in Northeast and Upper Midwest (90% of U.S. cases)
- High-Risk States
- Connecticut (Nantucket County: 1198 case/100,000)
- Delaware
- Maryland
- New Jersey
- New York
- Pennsylvania
- Rhode Island
- Wisconsin
- Moderate-Risk States
- Maine
- Massachusetts
- Minnesota
- New Hampshire
- Vermont
- High-Risk States
- Reference
- Concurrent Lyme and Babesiosis is common (n=1156)
- Coinfection occurs 10% in southern New England
- Reference
III. History
- 1975: Lyme Disease first reported in Lyme, Connecticut
- Cluster of new cases of Arthritis in children
- 1981: Borrelia Burgdorferi identified as cause
IV. Pathophysiology
- Borrelia Burgdorferi
- Causative Spirochete organism
- Carried by white tail deer
- Transmitted by Deer Ticks
- Natural reservoirs
- White-footed mouse and other small mammals
-
Deer Ticks or Black Legged Tick
- Vectors for several infections
- Borrelia Burgdorferi (Lyme Disease)
- Babesia Microti (Babesiosis)
- Anaplasma phagocytophila (causes HGA)
- Prior: Ehrilichia phagocytophila (Ehrlichiosis)
- Tick species
- Ixodes Scapularis
- Ixodes pacificus (West coast)
- Vectors for several infections
-
Deer Ticks have two year life cycle:
- Egg to Larva
- Larva to Nymph
- Nymph to Adult
- In endemic areas:
- Nymphs infected: 12-30%
- Adult ticks infected: 28-65%
- Nymphs outnumber adult ticks 10:1
- Nymphs are responsible for 90% of Lyme Disease cases
- Transmission relies on the time it takes for Borrelia to migrate from tick midgut to its Salivary Glands
- Nymphs must attach for >36-48 hours for transmission
- Adult ticks must attach for >48-72 hours for transmission
V. Differential Diagnosis
-
Erythema Migrans
- See Annular Lesion
- Cellulitis
- Tinea Corporis
- Granuloma Annulare
-
Arthropod Bite reaction
- Usually <5 cm, painful, develops in minutes to hours
- Rash is often pruritic
- Resolves within 48 hours without viral symptoms
- Other Ixodes tick (Deer Tick) borne infection
VI. Signs and Symptoms: Stage 1 (Early localized disease)
- Less than 20% of people recall Tick Bite
- Localized Erythema Chronicum Migrans at Tick Bite site (present in 80% of cases)
- See Erythema Migrans
- Expanding red Macule or Papule
- Size >=5 cm at outer ring diameter
- Rapid and prolonged expansion is unique (typically increases in diameter to >10-16 cm)
- Central clearing is variably present
- Onset within 3-30 days (typically 7-14 days) of Tick Bite and fades after 3-4 weeks
- Mild constitutional Symptoms (onset shortly after rash appears)
- Fever (also consider HGA or Babesiosis)
- Malaise
- Arthralgias (esp. Monoarthritis of the knee or hip)
- Headache
- Neck stiff
- Other skin lesions
VII. Signs and Symptoms: Stage 2 (Early disseminated disease)
- Cardiac (<10% of patients; onset typically within 1-2 months of infection)
- Atrioventricular Block (49% with third degree AV Block)
- Pericarditis
- Myocarditis
- Chest Pain
- Palpitations
- Dyspnea
- Syncope
- Musculoskeletal
- Arthralgias
- Myalgias
- Neurologic
- Bell's Palsy (or other Cranial NerveNeuropathy)
- Strongly consider empiric treatment for Lymes Disease with Bell's Palsy (esp. bilateral) in Lyme endemic regions
- Lymphocytic Meningitis or Encephalitis
- Often affebrile, with prolonged illness (7 days instead of typical 2 days for Viral Meningitis)
- Pseudotumor Cerebri
- Headache
- Vision changes
- Weakness
- Paresthesias
- Radiculopathy
- Nuchal Rigidity
- Bell's Palsy (or other Cranial NerveNeuropathy)
- Ophthalmologic
- Urologic
- Skin: Disseminated Erythema Migrans (most common Stage 2 finding)
- Multiple Erythema Migrans lesions (hematogenous spread of infection)
- Smaller lesions than with initial Erythema Migrans
- Lesions often lack central clearing
- Diffuse involvement (but spares palms and soles)
- Miscellaneous
- Regional Lymphadenopathy or General Lymphadenopathy
- Hepatitis
VIII. Signs and Symptoms: Stage 3 (Late Disseminated, chronic disease)
- Large Joint Arthritis
- Occurs in 10-60% of untreated Lyme Disease (most common presentation for disseminated lymes)
- Arthritis presents at approximately 6 months after infection onset
- Monoarticular or asymmetric Oligoarticular Arthritis (especially knees; hips may also be involved)
- Fever is less common than with other Septic Arthritis
- Persistent Joint Pain in 10-20% of patients despite appropriate Antibiotic treatment
- Neurologic (10-15% of untreated patients)
- See Stage 2 neurologic conditions
- Symptoms
- Classic triad
- Lymphocytic Meningitis
- Cranial Neuropathy (especially Bell's Palsy)
- Radiculoneuropathy
- Other manifestations
- Subacute encephalopathy
- Axonal Polyneuropathy
- Leukoencephalopathy
- Cerebellar Ataxia
- Mononeuritis multiplex
IX. Labs: Modified Two Tiered Lyme Test Protocol (modified 2019)
- Tier 1: Initial Lyme Titer
- Obtain polyvalent enzyme immunoassay (EIA such as ELISA), or immunofluorescence assay (IF)
- Not needed if Erythema Migrans in endemic areas
- False Positive Rate is high
- Positive results are reflexed to confirmation testing
- Tier 2: Lyme confirmatory testing (if tier 1 test equivocal or positive)
- Option 1: Lyme Serology Second Generation Tests (approved by FDA, 2019, preferred)
- New pathway established for tests with better Test Sensitivity, Test Specificity and precision than the first test
- Since 2019, modified 2 tier confirmation is with another enzyme immunoassay (EIA), and recommended by CDC
- Option 2: Lyme Western Blot (conventional, older protocol, replaced by option 1)
- Western Blot for Lyme IgM and IgG has been historically used for confirmation before 2019
- Higher False Negatives than EIA testing in acute and early disseminated Lyme Disease
- False Negative in 60-75% of patients without disseminated disease (decreases to 10% in later stages)
- With Lyme Serology, Test Specificity: 99-100%
- IgG must be positive for symptoms >4 weeks
- Option 1: Lyme Serology Second Generation Tests (approved by FDA, 2019, preferred)
- References
X. Labs: Other
- See Lyme Test
- Tests indicated in specific cases (in addition to two tiered protocol above)
- Synovial FluidLyme PCR
- Joint Aspiration in cases of suspected Lyme Arthritis
- Test Sensitivity approaches 100%
- Test Specificity 42 to 100%
- Cerebrospinal fluid (CSF) for Intrathecal Lyme Antibody production
- Indicated for neurologic symptoms
- C6 Peptide assay (IgG Enzyme Linked Immunosorbent Assay)
- Under study as of 2012 for replacement of the two tiered protocol
- Synovial FluidLyme PCR
- Precautions
- Borrelia Burgdorferi IgG and IgM
- Persists for years following effective Antibiotic treatment
- Positive test after treatment does not indicate failed Antibiotics or chronic infection
- Lyme urine Antigen
- High False Positive Rate and not recommended
- Borrelia Burgdorferi IgG and IgM
XI. Labs: General Tests to Consider (e.g. Identify Other Causes in Differential)
-
Complete Blood Count (CBC)
- Contrast with findings in Anaplasma and Babesia (Thrombocytopenia, Leukopenia or Neutropenia)
- Leukocytosis
- Anemia
- Comprehensive Metabolic panel
- Typically normal in Lyme Disease (but abnornal in Anaplasma and Babesia)
- Rheumatologic Testing
- Rheumatoid Factor (RF) negative
- C-Reactive Protenin positive
- Erythrocyte Sedimentation Rate (ESR) elevated
- Deer Tick borne infection testing (Peripheral Smear, PCR)
XII. Differential Diagnosis
- See Erythema Chronicum Migrans
- See Tick-Borne Illness
- See Deer Tick
- See Acute Monoarthritis
- Other Infections from Deer Ticks
- In addition to Lyme Disease, Deer Ticks transmit Babesiosis and Human Granulocytic Anaplasmosis
- Consider Parasite stain and Serology for Babesia and Anaplasma in febrile patients
- Babesia and Anaplasma are more commonly associated with Anemia, Leukopenia or Neutropenia
- Thrombocytopenia is seen with anaplasma
- Other tick borne infections with similar presentations to Lyme Disease
- Lone Star Tick borne STARI
- Similar appearance to Erythema Migrans
- Lone Star Tick borne STARI
XIII. Precautions
- Consider Lyme Disease in unexplained symptoms (Arthralgias, focal weakness) despite lack of bite history
- Fluctuating meningoencephalitis symptoms
- Cranial Nerve palsy (e.g. Bell's Palsy, especially if bilateral)
- Peripheral Neuropathy or radiculopathy
- New first-degree AV Block or Dysrhythmia
- New left-ventricular dysfunction
- However, avoid testing for Lyme Disease to explain behavioral disorders
- Avoid routine Lyme Disease Testing to explain psychiatric illness or behavioral disorders
- Information based on IDSA and CDC guidelines
- IDSA: Infectious Disease Society of America
- IDSA is considered standard of care recommendations
- Tertiary centers (e.g. Mayo) follow these guidelines
- Other guidelines (e.g. ILADS) are not reviewed here
- ILADS: International Lyme and Associated Diseases
- ILADS guidelines are considered controversial
XIV. Management: Deer Tick Bite
- See Deer Tick Bite (includes Antibiotic Prophylaxis After Known Deer Tick Bite)
- See Tick Removal
XV. Management: Stage 1 (Early Lyme Disease and Erythema Migrans)
-
Antibiotic treatment risks Jarisch-Herxheimer Reaction (affects 15% of patients)
- Borrelia is a Spirochete with potential for similar reaction to Antibiotics as for Syphilis
- Manifests as increased Temperature, myalgias and Arthralgias in first 24 hours of treatment
-
Doxycycline (Avoid in pregnancy and under age 9 years)
- Preferred oral agent due to cross-coverage of other tick-borne infections
- Adult: 100 mg orally twice daily for 10 to 21 days (typically 10 days)
- Child (age >8): 4 mg/kg orally divided twice daily (max 100 mg/dose) for 10-21 days (typically 10 days)
-
Amoxicillin
- Adult: 500 mg orally three times daily for 14 to 21 days (typically 14 days)
- Child: 50 mg/kg/day divided three times daily (max 500 mg/dose) for 14 to 21 days (typically 14 days)
-
Cefuroxime (Ceftin)
- Adult: 500 mg orally twice daily for 14 to 21 days (typically 14 days)
- Child: 30 mg/kg/day divided twice daily (max: 500 mg/dose) for 14 to 21 days (typically 14 days)
-
Macrolides have lower efficacy (consider other agents above if possible)
- Use only if allergic to above agents
- Azithromycin
- Adult: 500 mg daily for 7 to 10 days (typically 7 days)
- Child: 10 mg/kg daily for 7 to 10 days (typically 7 days)
- Clarithromycin
- Adult: 500 mg orally twice daily for 21 days
- Child: 7.5 mg/kg (max: 500 mg/dose) orally twice daily for 21 days
- Erythromycin
- Adult: 500 mg orally four times daily for 21 days
- Child: 12.5 mg/kg (max 500 mg/dose) orally four times daily for 21 days
- If suspect Cellulitis versus Erythema Migrans
- Augmentin 50 mg/kg/day divided bid or tid (up to 875 mg twice daily)
- Cefuroxime 30 mg/kg/day divided twice daily (up to 500 mg twice daily)
- Doxycycline 4 mg/kg divided twice daily (up to 100 mg twice daily)
-
Antibiotics to avoid (not indicated)
- Avoid First Generation Cephalosporins (Cephalexin)
- Avoid Fluoroquinolones
- Avoid Septra, Metronidazole, Penicillin G
XVI. Management: Stage 2 (Early disseminated with cardiac or neurologic findings)
- Indications for hospitalization and ParenteralAntibiotics
- New first degree AV Block with PR >300 ms
- Chest Pain, Syncope or Dyspnea
- Lyme Meningitis or Encephalitis
- New second or third degree AV Block
- Protocol: Indications to treat with agents as Stage 1 disease for 14-21 days
- Isolated Bell's Palsy or radiculopathy
- Asymptomatic, isolated first degree AV Block
- Protocol
- Obtain Lumbar Puncture for neurologic findings attributed to Lymes Disease
- Treat lyme Arthritis for 28 days
- Treat neurologic and carditis complications for 14 to 21 days
-
Ceftriaxone (Rocephin)
- Adult: 2g/day IV for 14 to 28 days
- Child: 75 mg/kg/day IV for 14 to 28 days
-
Cefotaxime (Claforan)
- Adult: 2g every 8 hours for 14 to 28 days
- Child: 150-200 mg/kg/day divided every 6 to 8 hours IV for 14-28 days
- Other Antibiotics
- Penicillin G IV may be used for lymes Meningitis and Lyme Arthritis
XVII. Management: Stage 3 (Late Disseminated Lyme Disease)
-
Arthritis
- Use same oral Antibiotic protocols as under Stage 1 - Erythema Migrans management for 28 days
- Persistent or recurrent Joint Swelling despite initial Antibiotics course
- Consider repeating a 4 week course of oral Antibiotics or 2-4 week course of Ceftriaxone
- Neurologic findings
- Use same intravenous Antibiotic protocols as under Stage 2 - early disseminated management
- Post-Lyme Disease syndrome of persistent Fatigue or cognitive difficulties
- No benefit to prolonged Antibiotic courses or other medication management
- Klempner (2013) Am J Med 126(8):665-9 +PMID:23764268 [PubMed]
XVIII. Management: Other Lyme Related Conditions
-
Borrelial Lymphocytoma
- Oral Doxycycline, Amoxicillin or Cefuroxime for 14 days
- Acrodermatitis Chronica Atrophicans
- Oral Doxycycline, Amoxicillin or Cefuroxime for 21 to 28 days
XIX. Complications: Post-Lyme Disease Syndrome
- Post-Lyme Disease Syndrome Criteria (reported in 10-20% of cases)
- Persistent vague symptoms >6 months after completing treatment
- Causes
- Idiopathic in most cases
- Untreated comorbid tickborne illness (e.g. Babesiosis)
- Comorbid unrelated medical condition
- Management
- Prolonged Antibiotic use is not recommended (beyond specific indications as above)
XX. Prevention
- See Prevention of Vector-borne Infection
- See Antibiotic Prophylaxis After Known Deer Tick Bite
- Lyme Vaccine (No longer available in U.S.)
-
Insecticide
- Acaricide applied to residential areas in mid May
- Provides 97% protection during peak nymph activity
XXI. Resources
- IDSA Guidelines
XXII. Reference
- Della-Giustina, Fox and Siegel (2021) Crit Dec Emerg Med 35(4): 17-23
- Hensley and Swaminathan in Herbert (2016) EM:Rap 16(7): 7-9
- Steere in Mandell (2000) Infectious Disease, p. 2504-14
- (2000) Med Lett Drugs Ther 42(1077): 37 [PubMed]
- (1997) Med Lett Drugs Ther 39(1000) [PubMed]
- Fix (1998) JAMA 279(3): 206-10 [PubMed]
- Lantos (2021) Clin Infect Dis 72(1):e1-e48 +PMID: 33417672 [PubMed]
- Pace (2020) Am Fam Physician 101(9): 530-40 [PubMed]
- Rahn (1998) Postgrad Med 103(5):51-70 [PubMed]
- Still (1997) Postgrad Med 102(1):65-72 [PubMed]
- Verdon (1997) Am Fam Physician, 56(1): 427-436 [PubMed]
- Nadelman (1995) Am J Med 98:15S-24S [PubMed]
- Stanek (2003) Lancet 362:1639-47 [PubMed]
- Wormser (2006) Clin Infect Dis 43(9):1089-134 [PubMed]
- Wright (2012) Am Fam Physician 85(11): 1086-93 [PubMed]