From: Subject: Best Dx/Best Rx: Lyme Disease Date: Wed, 3 Jun 2009 21:54:59 -0700 MIME-Version: 1.0 Content-Type: multipart/related; type="text/html"; boundary="----=_NextPart_000_0292_01C9E495.F0AD7790" X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0292_01C9E495.F0AD7790 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.acpmedicine.com/acp/newrxdx/rxdx/dxrx0707.htm Best Dx/Best Rx: Lyme Disease



Lyme = Disease

David C. Tompkins, M.D.
Benjamin J. Luft, M.D.=20

State University of New York at Stony Brook =

Defin= ition/Key=20 Clinical Features
Diffe= rential=20 Diagnosis
Best = Tests
Best = Therapy
Best = References

Definition/Key=20 Clinical Features

Early Localized Disease=20
  • Erythema migrans in up to 85% of exposed = persons=20
    • Appears 3=9630 days (mostly 7=9610 days) = after=20 exposure=20
    • Usually at the site of tick bite (knees, = axilla,=20 groin)=20
    • Red macule or papule, expands over days to=20 weeks=20
    • Can appear as target lesion with central = clearing,=20 vesicular or necrotic areas=20
    • Can become multifocal
  • Other common symptoms: arthralgias, myalgias,=20 conjunctivitis, meningismus, regional lymphadenopathy=20
  • Some patients asymptomatic
    Early Disseminated Disease=20
    • Arthritis (60% of untreated patients)=20
      • Begins weeks to years after initial = infection=20
      • Episodes of swelling and pain, primarily of = large=20 joints=20
      • Arthralgias, migratory arthritis, and = chronic=20 arthritis, usually of the knees
    • Acute cardiac involvement (4% to 10% of = untreated=20 patients)=20
      • Most common: fluctuating atrioventricular = (AV)=20 block=20
      • Occasional: acute myopericarditis, mild left = ventricular dysfunction=20
        • Duration usually brief (days to = weeks)=20
    • Acute neurologic abnormalities (10% to 15% of = untreated=20 patients)=20
      • Meningitis, meningoencephaitis, myelitis, = cranial=20 neuropathies, radiculitis
    Late=20 Persistent Disease=20
    • Inflammatory joint disease for longer than 1 = year (10%=20 of untreated patients)=20
      • Primarily large joints (most often the = knee)=20
      • May eventuate in joint destruction =
    • Chronic neurologic problems (5% of untreated=20 patients)=20
      • Encephalopathy ranging from mild cognitive = impairment=20 to dementia=20
      • Chronic axonal polyneuropathy =
    3D""=20=20 bac= k to=20 top

    Differential = Diagnosis

    Early Localized=20 Disease=20
    • Erythema migrans=20
      • Allergy to tick saliva=20
      • Cellulitis=20
      • Southern tick-associated rash illness = (STARI)=20
    Early Disseminated = Disease=20
    • Arthritis=20
      • Bacterial arthritis (gonococcal, = nongonococcal)=20
      • Crystalline arthropathy=20
      • Viral arthritis (hepatitis B, = parvovirus)=20
    • Cardiac involvement (AV block)=20
      • Ischemic heart disease=20
      • Fibrosis of conduction system=20
      • Medication
    • Neurologic abnormalities=20
      • Cranial neuropathy=20
        • Herpes simplex virus=20
        • Varicella zoster virus=20
        • Idiopathic
      • Meningitis=20
        • Bacterial=20
        • Viral=20
        • Malignancy=20
        • Medications (NSAIDS,=20 trimethoprim-sulfamethoxazole)=20
        • Sarcoid =
    Late Persistent Disease=20
    • Arthritis=20
      • Osteoarthritis=20
      • Crystalline arthropathy=20
      • Mycobacterial and fungal infection=20
    3D""=20=20 bac= k to=20 top

    Best=20 Tests

    • Characteristic clinical findings in a patient = with tick=20 exposure in an endemic area, plus positive serologic test results, = confirm=20 diagnosis=20
    • Erythema migrans eliminates need for positive = test=20 results before treatment=20
    • Serologic testing=20
      • Insensitive for several weeks from = onset=20
      • Per CDC, perform ELISA or IFA first; if = positive or=20 equivocal, do Western blot on same serum=20
      • Western blot results=20
        • IgM positive if 2/3 bands reactive: 23 kd; = 39 kd; 41=20 kd=20
        • IgG positive if 5/10 bands reactive: 18 = kd; 23 kd;=20 28 kd; 30 kd; 39 kd; 41 kd; 45 kd; 58 kd; 66 kd; 93 kd =
      • Tests do not detect titer rises=20
    3D""=20=20 bac= k to=20 top

    Best=20 Therapy

    Antibiotic Therapy=20

    • Early disease (local and disseminated)=20
      • Amoxicillin, 500 mg t.i.d. for 14=9621 = days=20
        • Preferred in children and pregnant = women=20
        • Cost/21 days: $16
      • Doxycycline, 100 mg b.i.d. for 14=9621 = days=20
        • Cost/21 days: $29
      • Cefuroxime axetil, 500 mg b.i.d. for 14=9621 = days=20
        • Cost/21 days: $450 =
    • Jarisch-Herxheimer reaction in 10% during = first 24 hr of=20 antibiotics: higher fever, redder rash, or greater pain=20
      • Treat with NSAID or aspirin=20
    Treatment of = Complications=20
    • Neurologic=20
      • Facial palsies=20
        • Oral regimens (above) for 14=9621 days; = some experts=20 suggest 30 days of antibiotic=20
        • Neurologic evaluation (CSF = analysis)
      • Meningitis or encephalitis=20
        • Ceftriaxone, 2 g I.V., q.d., for 14=9628 = days=20
        • Penicillin, 18=9624 million units I.V. = divided 4=966=20 times/day for 14=9628 days
      • Carditis=20
        • First-degree AV block: oral regimen (see = early=20 infections)=20
        • Second-degree AV block: see = meningitis=20
      • Arthritis=20
        • Doxycycline, 100 mg p.o., b.i.d., for = 30=9660=20 days=20
          • Cost/mo: $42
        • Amoxicillin, 500 mg p.o., q.i.d., for = 30=9660=20 days=20
          • Cost/mo: $23
        • Ceftriaxone, 2 g I.V., q.d., for 14=9628 = days=20
        • Penicillin G, 20 million units I.V. in = four divided=20 doses daily for 14=9628 days=20
        • Persistent symptoms after antibiotics:=20 anti-inflammatory drugs or arthroscopic synovectomy=20
    3D""=20=20 bac= k to=20 top

    Best References

    Barbour AG, et al: Microbiol Rev 50:381, 1986 = [PMID=20 3540570]

    Massarotti EM, et al: Am J Med 92:396, 1992 [PMID = 1313637]

    MMWR Morb Mortal Wkly Rep 44:590, 1995 [PMID=20 7623762]

    Seltzer EG, et al: JAMA 283:609, 2000 [PMID=20 10665700]

    Steere AC, et al: J Infect Dis 154:295, 1986 = [PMID=20 3722867]

    The authors have no commercial relationships with = manufacturers of=20 products or providers of services discussed in this module.=20

    August=20 2006