High Yield Topics

Lyme Disease

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Ovid: 5-Minute Orthopaedic Consult

Editors: Frassica, Frank J.; Sponseller, Paul D.; Wilckens, John H.
Title: 5-Minute Orthopaedic Consult, 2nd Edition
> Table of Contents > Lyme Disease

Lyme Disease
Paul D. Sponseller MD
Basics
Description
  • Lyme disease is an immune-mediated disorder.
  • It may include rash, arthritis, synovitis, carditis, or neurologic manifestations.
  • Children and adults are affected equally.
  • Classification (1):
    • Acute stage:
      • Rash
      • Early arthritis
    • Chronic stage:
      • Arthritis
      • Carditis
      • Neuritis
  • Synonym: Deer tick disease
General Prevention
  • Awareness of endemic areas
  • Avoidance of deer tick exposure
Epidemiology
Incidence
  • The incidence varies with the region of the country, but it has been reported in most states.
  • 3 major endemic areas in the United States:
    • Upper mid-Atlantic area from Massachusetts to Maryland
    • Upper Midwest (especially Wisconsin and Minnesota)
    • Western states of Oregon, Utah, Nevada, and California
Risk Factors
  • Endemic area
  • Deer tick exposure
  • HLA-DR4 antigen haplotype
Genetics
The HLA-DR4 haplotype predicts increased risk of disease.
Etiology
  • Lyme disease is a reaction to an infection by the spirochete Borrelia burgdorferi, which is transmitted by the deer tick, Ixodes dammini(1,2).
  • The disease was characterized after an epidemic of involvement in Old Lyme, Connecticut, in the mid-1970s (3,4).
    • Since then, other endemic areas have been identified.
Diagnosis
Signs and Symptoms
  • Acute:
    • Spreading rash known as erythema chronicum migrans, beginning 3–30 days after a tick bite
    • Fever
    • Headache
    • Malaise
    • Migratory arthralgias and myalgias
  • Chronic:
    • Swelling of large joints, most commonly the knee
    • Involvement of 1 or more joints
    • Pain, which may be minimal, as in juvenile rheumatoid arthritis, or acute, resembling bacterial arthritis
    • Cardiac involvement, possibly including atrioventricular block or myocarditis
    • Neurologic involvement, possibly including the 7th cranial nerve (facial) palsy, meningoencephalitis, or peripheral neuropathy
Physical Exam
  • Inspect the patient’s skin for the spreading, oval rash.
  • Question about a rash occurring earlier.
  • Examine for cranial nerve or peripheral nerve palsy.
  • Examine all joints for effusion, even if painless.
  • Listen to the patient’s heart.
Tests
Lab
  • The ESR usually is elevated (3,5).
  • Tests for Lyme disease include 2 methods of antibody detection.
    • Enzyme-linked immunosorbent assay for spirochete:
      • Sensitive but not specific
      • A titer of >1:80 is considered positive.
      • If positive, this test should be followed by the Western blot test, a more specific gel electrophoresis technique.
    • Arthrocentesis:
      • Not a specific test for Lyme disease, but often performed to rule out other disorders
      • The white blood cell count is 25,000–90,000 and may include up to 95% polymorphonuclear leukocytes.
      • The spirochete is not recoverable from joint fluid.
  • Electrocardiography may be indicated to show atrioventricular block.
Imaging
  • Plain radiographs of the affected area are indicated (6).
  • Joint changes may include soft-tissue
    swelling in early stages, osteopenia if the inflammation has been
    present for several weeks, and joint space narrowing if it has been
    chronic.
Pathological Findings
  • Usually, no pathologic specimens are taken or required for diagnosis.
  • When the joint lining is examined by biopsy, it shows nonspecific synovitis.
Differential Diagnosis
  • The diagnosis of juvenile rheumatoid
    arthritis requires at least 6 weeks of continued arthritis, but the
    arthritis does not respond to antibiotics, in contrast to Lyme disease.
  • Bacterial arthritis usually produces more acute pain and fever and does not have a characteristic prodromal rash.
  • Rheumatic fever should be excluded.

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Treatment
General Measures
  • Consult other specialists, such as those in infectious disease, neurology, rheumatology, or cardiology, as appropriate.
  • Arrange diagnostic testing.
Activity
Restrict the patient’s activity in the presence of substantial joint, cardiac, or neurologic involvement.
Medication
  • Start treatment with oral (early stages of disease) penicillin or amoxicillin empirically.
  • Administer these drugs intravenously if the disease is treated later.
  • Tetracycline is an option for children who are >8 years old.
    • It should not be used in younger children because of potential discoloration of the teeth.
Surgery
Synovectomy is a rare option for chronic disease that does not respond to initial antibiotic therapy.
Follow-up
Prognosis
Prognosis usually is good, unless late joint changes or neurologic complications have occurred.
Complications
  • Carditis (conduction block, myocarditis)
  • Neurologic involvement (e.g., cranial or peripheral nerve palsy, meningoencephalitis)
Patient Monitoring
  • Follow patients daily to weekly to monitor response to therapy.
  • Possibly admit patients to the hospital if cardiac or neurologic involvement is severe.
References
1. Steere AC. Lyme disease. N Engl J Med 1989;321: 586–596.
2. Phillips SE, Harris NS, Horowitz R, et al. Lyme disease: scratching the surface. Lancet 2005;366: 1771.
3. DePietropaolo DL, Powers JH, Gill JM, et al. Lyme disease: what you should know. Am Fam Physician 2005;72:309.
4. Kulie T, Vogt K, Sevetson E, et al. Clinical inquiries. When should you order a Lyme titer? J Fam Pract 2005;54:1084–1086,1088.
5. Cristofaro RL, Appel MH, Gelb RI, et al. Musculoskeletal manifestations of Lyme disease in children. J Pediatr Orthop 1987;7:527–530.
6. Rose CD, Fawcett PT, Eppes SC, et al. Pediatric Lyme arthritis: clinical spectrum and outcome. J Pediatr Orthop 1994;14:238–241.
Miscellaneous
Codes
ICD9-CM
  • 714.0 Inflammatory arthritis
  • 727.0 Synovitis
Patient Teaching
  • Patients should be educated about prevention of re-exposure, and the family should be so counseled.
  • They should also be informed about the late signs and symptoms of cardiac and neurologic involvement.
FAQ
Q: Should patients with tick bites be treated prophylactically for Lyme disease?
A: Because the risk of Lyme disease per exposure is low, this is not recommended generally.

Q: Does Lyme disease always follow the classic sequence and presentation?
A: No. Many atypical forms are seen, so an index of suspicion is needed.

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