Lyme disease

Background

National Lyme disease risk map with 4 categories of risk.

Ixodes tick

• Tick Borne - Ixodes black-legged ticks
• Endemic Areas: NE, E US Coasts
• Caused by spirochete Borrelia burgdorferi
• Peak in May to Aug
• 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

3 Distinct Stages - Not all patients suffer all stages, and stages may overlap with remiss ions b/w stages

Early Localized Infection (7-14d)

• Erythema Chronicum Migrans: Occurs at site of tick bite, beginning w/ red macule that expands outward. Starts 3-30 days after bite and occurs in 70-80% of cases.
• Fatigue, low grade fever, migrating arthralgia, lymphadenopathy, headache, N/V, abd pain

Early Disseminated Infection (Days to weeks)

• Skin-mult annular lesions sparing palm/soles
• Nervous System-fluctuating meningoencephalitis, HA, N/V, CN palsies (ie 7th-can be bilateral) peripheral neuropathy, radiculopathy
• Cardiovascular: AV blocks, RBBB, dysrhythmias, LV dysfunction
• Eye: Conjunctivitis, keratitis, retinal detachment, optic neuritis

Late Disseminated Infection (Months to Years)

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

Differential Diagnosis

• Enterovirus
• Hepatitis
• Mononucleosis
• Connective tissue disease
• Erythema Multiforme
• CAD
• Acute rheumatic fever
• Aseptic Meningitis
• HSV encephalitis
• Bell's Palsy
• Multiple Sclerosis
• Guillain-Barre
• Cerebral Vascultitis

Polyarthritis

Algorithm for Polyarticular arthralgia

• Fibromyalgia
• Juvenile idiopathic arthritis
• Lyme disease
• Osteoarthritis
• Psoriatic arthritis
• Reactive poststreptococcal arthritis
• Rheumatoid arthritis
• Rheumatic fever
• Serum sickness
• Systemic lupus erythematosus
• Serum sickness–like reactions
• Viral arthritis

Tick Borne Illnesses

• Babesiosis
• Colorado tick fever
• Ehrlichiosis
• Heartland virus
• Lyme
• Murine typhus
• Rocky mountain spotted fever
• Southern tick-associated rash illness (STARI)
• Tick paralysis
• Tularemia

Diagnosis

• 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 pts with neuro findings (facial nerve palsy, meningoencephalitis, etc)
  • CNS Lyme disease will be treated with ceftriaxone
• Arthrocentesis, serologic testing of fluid

Management

No risk when duration of attachment <24 hrs

Prophylaxis

• Adult: Doxycycline 200 mg PO x1
• Child >8: 4 mg/kg up to 200 mg 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
  • Doxycycline 100 mg PO BID x 14-21 days
    • Also treats human granulocytic ehrlichiosis
  • Amoxicillin 500 mg PO TID x 14-21 days
    • Preferred in pregnant, lactating, children <8
  • Cefuroxime axetil 500 mg PO BID x 14-21 days
  • Macrolides-not first line
• Jarisch-Herxheimer like reaction can occur in first 24 hrs of treatment (fevers, chills, myalgia, tachycardia)

Early Disemminated

• Doxycycline (see above dosing)

• Amoxicillin (See above dosing)

Lyme Meningitis

• Ceftriaxone 2g IVq12h x 14-28 days
  • Doxycycline 200-400 mg/d divided into two doses q day x 10-28 days
  • Penicillin G, Cefotaxime

Cardiac Disease

• Mild (1st degree AV with PR <0.3 sec)
  • Doxycycline/Amoxicillin PO
• Severe (HIgh-degree AV block)
  • Ceftriaxone/Pen G IV

Arthritis

• Doxycycline, Amoxicillin PO, as effective as parenteral
• Ceftriaxone/Pen G IV

Disposition

Outpatient

• Early Disease
• Late Disease: If chronic neurologic/arthritic manifestations may be able to manage as outpt
• F/u with PMD, rheum, ID
  

Admission

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

See Also

• Tick Borne Illnesses