Lyme disease

Lyme disease

• erythema migrans
  • 'bulls-eye' rash is typically at the site of the tick bite
  • typically develops 1-4 weeks after the initial bite but may present sooner
  • usually painless, more than 5 cm in diameter and slowlly increases in size
  • present in around 80% of patients
    present in around 80% of patients
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    .
• systemic features
  • headache
  • lethargy
  • fever
  • arthralgia

Erythema migrans: Bulls-eye rash typically seen at the site of the tick bite

Erythema migrans

• cardiovascular
  • heart block
    Heart block is an important cause of death in Lyme disease
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    Importance: 93
  • peri/myocarditis
• neurological
  • facial nerve palsy
    facial nerve palsy
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  • radicular pain
  • meningitis

ECG from a patient with Lyme disease showing 3rd degree heart block with LBBB indicating that the escape rhythm is from the right bundle - e Image used on license from Dr Smith, University of Minnesota

• NICE recommend that Lyme disease can be diagnosed clinically if erythema migrans is present
  Lyme disease can be diagnosed clinically if erythema migrans is present
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  • erythema migrans is therefore an indication to start antibiotics
• enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test
  ELISA is the first-line investigation for suspected Lyme disease in patients with no history of erythema migrans
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  Importance: 59
  • if negative and Lyme disease is still suspected in people tested within 4 weeks from symptom onset, repeat the ELISA 4-6 weeks
    repeat the ELISA 4-6 weeks
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    after the first ELISA test. If still suspected in people who have had symptoms for 12 weeks or more then an immunoblot test should be done
  • if positive or equivocal then an immunoblot test for Lyme disease should be done
    For patients with suspected Lyme disease, If the ELISA is positive or equivocal perform an immunoblot test
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    Importance: 24

• tick bites can be a relatively common presentation to GP practices, and can cause significant anxiety
• if the tick is still present, the best way to remove it is using fine-tipped tweezers, grasping the tick as close to the skin as possible and pulling upwards firmly
  remove it is using fine-tipped tweezers, grasping the tick as close to the skin as possible and pulling upwards firmly
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  . The area should be washed following.
• NICE guidance does not recommend routine antibiotic treatment to patients who've suffered a tick bite

• doxycycline
  First line treatment for early Lyme disease is a 14-21 day course of oral doxycycline
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  Importance: 57
  if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)
  Amoxicillin is an alternative to treat early Lyme disease if doxycycline is contraindicated such as in pregnancy
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  Importance: 66
  • people with erythema migrans should be commenced on antibiotic without the need for further tests
    people with erythema migrans should be commenced on antibiotic without the need for further tests
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• ceftriaxone
  IV ceftriaxone should be used as first-line treatment of Lyme disease with disseminated or central nervous system involvement
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  Importance: 97
  if disseminated disease
• Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after first dose of antibiotic (more commonly seen in syphilis, another spirochaetal disease)