Lyme Disease, Emergency Medicine

Basics

Description

Most common tick-borne illness in North America
Endemic in Northeast, Upper Midwest, and northwestern California

Etiology

Peak April " “November; 80 " “90% in summer months
Spirochete Borrelia burgdorferi introduced by Ixodes tick:
- Ixodes dammini (deer tick) most common
<50% of patients recall tick bite.
Pathogenesis " ”combination of:
- Organism-induced local inflammation
- Cytokine release
- Autoimmunity
No person-to-person transmission
Borrelia miyamotoi, a spirochete related to B. burgdorferi, has recently been described as causing disease similar to Lyme disease.

Diagnosis

Signs and Symptoms

Stage I (early): ‚

Onset few days to a month after tick bite (arthropod transmission)
30 " “50% of patients recall tick bite.
Erythema chronicum migrans (ECM):
- Pathognomonic finding:
  - Bull 's-eye rash
- Maculopapular, irregular expanding annular lesion:
  - Single or multiple
  - Central clearing with red outer border
  - Diameter >5 cm
Regional adenopathy
Low-grade intermittent fever
Headache
Myalgia
Arthralgias
Fatigue
Malaise

Stage II (secondary, disseminated): ‚

Days to weeks after tick bite
Intermittent and fluctuating symptoms with eventual disappearance
Triad of aseptic meningitis, cranial neuritis, and radiculoneuritis:
- Facial (Bell) palsy most common cranial neuritis
- May present without rash
- Prognosis generally good
Cardiac:
- Tachycardia
- Bradycardia
- Atrioventricular block
- Myopericarditis

Stage III (tertiary, late): ‚

Onset >1 yr after disease onset
Acrodermatitis chronica atrophicans:
- Extensor surfaces of extremities, especially lower leg
- Initial edematous infiltration evolving to atrophic lesions
- Resembles scleroderma
Arthritis:
- Brief arthritis attacks
- Monoarthritis
- Oligoarthritis
- Occasionally migratory
- Most common joints (descending order):
  - Knee
  - Shoulder
  - Elbow

Other: ‚

GI:
- Hepatitis
- Right upper quadrant pain
Ocular:
- Keratitis
- Uveitis
- Iritis
- Optic neuritis
Jarisch " “Herxheimer reaction:
- Worsening of symptoms a few hours after treatment initiated
- More common in patients with multiple ECM lesions
Babesiosis occurs simultaneously in endemic areas.

Persistent Lyme disease: ‚

Articular and neurologic symptoms despite treatment:
- Chronic axonal polyneuropathy or encephalopathy

Recurrent Lyme disease: ‚

Relapse despite treatment
2nd episodes less severe

More likely than adults to be febrile
Only 50% of children with arthralgias have history of ECM.
Facial palsy is accompanied by aseptic meningitis in 1/3.
Asymptomatic cardiac involvement with abnormal ECGs
Appropriately treated children have excellent prognosis for unimpaired cognitive functioning.
Untreated children may have keratitis

No clear evidence that Lyme disease during pregnancy causes harm to fetus ‚
History

History of tick bite in endemic areas
Flu-like illness in the summer

Physical Exam

Rash
Joint, cardiac, and neurologic findings in later organ involvement

Essential Workup

Clinical diagnosis:
- Presence of ECM obviates serologic tests.
Careful search for tick
Lumbar puncture when meningeal signs
Arthrocentesis for acute arthritis
ECG

Diagnosis Tests & Interpretation

Lab

CBC:
- Leukocytosis
- Anemia
- Thrombocytopenia
ESR:
- >30 mm/hr
- Most common lab abnormality
Electrolytes, BUN, creatinine, glucose
Liver function tests:
- Elevated liver enzymes ( Ž ³-glutamyl transferase most common)
Culture:
- Low yield
- Not indicated
CSF:
- Pleocytosis
- Elevated protein
- Obtain CSF spirochete antibodies.
Special tests:
- Serology:
  - Obtain ELISA, immunofluorescence assay, and western blot when disease is suggested without ECM lesion.
  - Antibodies may persist for months to years.
  - Positive serology or previous Lyme disease does not ensure protective immunity.
- Polymerase chain reaction assay:
  - Highly specific and sensitive
  - Not available for routine use
- Joint fluid:
  - Cryoglobulin increased 5-fold compared with serum
- Joint films may show soft tissue, cartilaginous, osseous changes.

Differential Diagnosis

Other tick-borne illnesses:
- Deer tick usually larger (1 cm) than Ixodid ticks (1 " “2 mm)
- Rocky Mountain spotted fever
- Tularemia
- Relapsing fever
- Colorado tick fever
- Tick-bite paralysis
Rheumatic fever:
- Rash of erythema marginatum
- Temporomandibular joint arthritis more common than in Lyme disease
- Valvular involvement rather than heart block
- Chorea may be isolated finding.
Viral meningitis
- Syphilis
- Septic arthritis
- Parvovirus B19 infection " ”polyarticular arthritis
- Infectious endocarditis
- Juvenile rheumatoid arthritis
- Reiter syndrome
- Brown recluse spider bite
- Fibromyalgia
- Chronic fatigue syndrome

Treatment

Initial Stabilization/Therapy

20 mL/kg of 0.9% NS IV fluid bolus for dehydration
IV access for neurologic and cardiac involvement
Cardiac monitoring
Temporary pacemaker for heart block

Ed Treatment/Procedures

Remove tick:
- Disinfect site.
- With blunt instrument, grasp tick close to skin and pull upward with gentle pressure.
Medications:
- Aspirin as adjunctive therapy for cardiac involvement
- NSAIDs for arthritis or arthralgias
Vaccine (Lymerix) for prevention of disease:
- A recombinant surface protein
- For persons in high/moderate risk areas
- For travelers to endemic areas
- 3 doses (0 " “1 mo " “2 mo)
Stage I:
- Amoxicillin, doxycycline (for those ≥8 yr of age), or cefuroxime (21 days)
- Azithromycin (14 " “21 days)
- Parenteral therapy in pregnant patients
Stage II:
- Oral therapy for isolated Bell palsy and mild involvement:
  - Amoxicillin with probenecid (30 days) or doxycycline (avoid if pregnant or ≥8 yr old; 10 " “21 days)
- Parenteral therapy for more severe involvement (meningitis, carditis, severe arthritis):
  - Ceftriaxone, cefotaxime (14 " “21 days), or penicillin G (14 " “28 days)
Stage III:
- Parenteral therapy:
  - Penicillin G, cefotaxime (14 " “21 days), or ceftriaxone (14 " “28 days)

Medication

First Line

Amoxicillin: 500 mg (peds: 50 mg/kg/24 h) PO TID for those <8 yr of age or unable to tolerate doxycycline.
Aspirin: 80 " “100 mg/kg/d (peds: 50 " “100 mg/kg/d in 6 div. doses) PO; do not exceed 4 g/24 h (peds: Do not exceed 120 mg/kg/24 h or 4 g/24 h)
Doxycycline: 100 mg PO BID for 14 " “21 days for children ≥8 yr and adults (except if pregnant)
Ceftriaxone: 2 g (peds: 100 mg/kg/24 h) IV daily (1st line for late-term disease)

Second Line

Azithromycin: 500 mg PO daily
Cefuroxime axetil, 500 mg BID (all ages)
Cefotaxime: 2 g (peds: 100 " “150 mg/kg/24 h) IV q8h
Penicillin G: 20 " “24 million U IV q4 " “6h
Probenecid: 500 mg PO TID

Follow-Up

Disposition

Admission Criteria

Meningoencephalitis
Telemetry/ICU admission for carditis

Discharge Criteria
Patients treated with oral therapy ‚

Pearls and Pitfalls

Duration of treatment for later organ involvement will be ≥30 days.
Be aware of coinfections with Anaplasmosis and Babesiosis.

Additional Reading

American Academy of Pediatrics: Report of the Committee on Infectious Diseases. 29th ed. Elk Grove, CA: Ill; 2012.
Kowalski ‚ TJ, Tata ‚ S, Berth ‚ W, et al. Antibiotic treatment duration and long-term outcomes of patients with early lyme disease from a lyme disease-hyperendemic area. Clin Infect Dis. 2010;50:512 " “520.
Marques ‚ AR. Lyme disease: A review. Curr Allergy Asthma Rep. 2010;10:13 " “20.
Steere ‚ AC, Coburn ‚ J, Glickstein ‚ L. The emergence of Lyme disease. J Clin Invest. 2004;113(8):1093 " “1101.

Codes

ICD9

088.81 Lyme Disease
320.7 Meningitis in other bacterial diseases classified elsewhere
711.80 Arthropathy associated with other infectious and parasitic diseases, site unspecified
422.0 Acute myocarditis in diseases classified elsewhere
377.30 Optic neuritis, unspecified

ICD10

A69.20 Lyme disease, unspecified
A69.21 Meningitis due to Lyme disease
A69.23 Arthritis due to Lyme disease
A69.29 Other conditions associated with Lyme disease
A69.22 Other neurologic disorders in Lyme disease
A69.2 Lyme disease

SNOMED

23502006 Lyme disease (disorder)
33937009 Lyme arthritis (disorder)
230150008 Meningitis in Lyme disease (disorder)
77863005 Lyme carditis (disorder)
66760008 Optic neuritis (disorder)

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