Doctor123.org

Lyme Disease, Emergency Medicine

Basics

Description

- <50% of patients recall tick bite. - Pathogenesis " ”combination of: - Organism-induced local inflammation - Cytokine release - Autoimmunity

- Onset few days to a month after tick bite (arthropod transmission) - 30 " “50% of patients recall tick bite. - Erythema chronicum migrans (ECM): - Pathognomonic finding: - Maculopapular, irregular expanding annular lesion: - Single or multiple - Central clearing with red outer border - Diameter >5 cm

- Cardiac: - Tachycardia - Bradycardia - Atrioventricular block - Myopericarditis

- Arthritis: - Brief arthritis attacks - Monoarthritis - Oligoarthritis - Occasionally migratory - Most common joints (descending order):

- GI: - Hepatitis - Right upper quadrant pain

- Ocular: - Keratitis - Uveitis - Iritis - Optic neuritis

- CBC: - Leukocytosis - Anemia - Thrombocytopenia

- Culture: - CSF: - Pleocytosis - Elevated protein - Obtain CSF spirochete antibodies.

- 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.

  • 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 inflammationCytokine releaseAutoimmunity
  • 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:Maculopapular, irregular expanding annular lesion:Single or multipleCentral clearing with red outer borderDiameter >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 neuritisMay present without rashPrognosis generally good
  • Cardiac:TachycardiaBradycardiaAtrioventricular blockMyopericarditis

Stage III (tertiary, late): ‚

  • Onset >1 yr after disease onset
  • Acrodermatitis chronica atrophicans:Extensor surfaces of extremities, especially lower legInitial edematous infiltration evolving to atrophic lesionsResembles scleroderma
  • Arthritis:Brief arthritis attacksMonoarthritisOligoarthritisOccasionally migratoryMost common joints (descending order):

Other: ‚

  • GI:HepatitisRight upper quadrant pain
  • Ocular:KeratitisUveitisIritisOptic neuritis
  • Jarisch " “Herxheimer reaction:Worsening of symptoms a few hours after treatment initiatedMore 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:LeukocytosisAnemiaThrombocytopenia
  • ESR:>30 mm/hrMost common lab abnormality
  • Electrolytes, BUN, creatinine, glucose
  • Liver function tests:Elevated liver enzymes ( Ž ³-glutamyl transferase most common)
  • Culture:
  • CSF:PleocytosisElevated proteinObtain 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 sensitiveNot available for routine useJoint fluid:Cryoglobulin increased 5-fold compared with serumJoint 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 feverTularemiaRelapsing feverColorado tick feverTick-bite paralysis
  • Rheumatic fever:Rash of erythema marginatumTemporomandibular joint arthritis more common than in Lyme diseaseValvular involvement rather than heart blockChorea may be isolated finding.
  • Viral meningitisSyphilisSeptic arthritisParvovirus B19 infection " ”polyarticular arthritisInfectious endocarditisJuvenile rheumatoid arthritisReiter syndromeBrown recluse spider biteFibromyalgiaChronic 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 involvementNSAIDs for arthritis or arthralgias
  • Vaccine (Lymerix) for prevention of disease:A recombinant surface proteinFor persons in high/moderate risk areasFor travelers to endemic areas3 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)