Lyme Disease

Question 1

Define lyme disease

Answer 1

Infection caused by a group of spiral-shaped bacteria (spirochetes) which are transmitted to humans following a bite from an infected tick.

Question 2

Aetiology of Lyme disease

Answer 2

Borrelia burgdorferi
Spread by ticks (ixodes)
Grassy, wooded areas with deer in England and Scottish highlands

RF: hiking

Question 3

Symptoms of Lyme disease

Answer 3

3 stages: rash → malaise, carditis, meningitis → CNS signs
1. Early localised: Erythema migrans rash (bullseye, 1-4 weeks)
2. Early disseminated
- Multiple secondary erythema migrans (disseminated)
- Arthritis (mono, migratory, large joints)
- Malaise
- Neuro: meningitis/encephalitis, nerve palsies e.g. Bell’s, mononeuritis multiplex, radiculopathy
- Heart: myocarditis -> pericarditis, heart block
- Eyes: uveitis/keratitis
- Trouble with memory or concentration
3. Late dieemsinated
- CNS/PNS disease
- Oligoarthritis
- Acrodermatitis chronic

+ flu-like symptoms 4-12 weeks post infection

Question 4

Differentials for lyme disease

Answer 4

Tick bite hypersensitivity reaction (within 48hrs bite)
Cellulitis
Erythema multiforme
Franuloma annulare
Spider bite (non-UK)
Tick-borne encephalitis
Urticaria

Question 5

Investigations for Lyme disease

Answer 5

Erythema migrans present → diagnose, give abx

NO → ELISA → immunoblot test
If symptoms remain despite negative ELISA → repeat 4-6 weeks after

Joint pain → Joint aspiration (exclude septic arthritis)

Question 6

Management for Lyme disease

Answer 6

MDT
Prevent tick-bites, remove any ticks

3 weeks PO Abx
- Doxycycline 100mg BD for 21 days
- Alt: Amoxicillin
- PenAll: Azithromycin (17 days only)
- 2-4 weeks IV ceftriaxone
Ongoing: second course abx/consider alternative diagnosis/reinfection/chronic

Question 7

Advice for Lyme disease

Answer 7

It is a bacterial infection treated with antibiotics.
Most people recover completely.
Prompt antibiotic treatment reduces the risk of further symptoms developing and increases the chance of complete recovery.
It may take time to get better, but their symptoms should continue to improve in the months after antibiotic treatment.
They may need additional treatment for symptom relief.

May have a Jarisch -Herxheimer reaction to abx:
This causes a worsening of symptoms early in treatment.
It can happen when large numbers of bacteria in the body are killed.
It does not happen to everyone treated for Lyme disease.
They should contact their doctor and keep taking their antibiotics if their symptoms worsen.

Question 8

Complications of Lyme disease

Answer 8

Chronic Lyme disease: fatigue, pain, joint or muscle aches post-treatment
Neuro: chronic meningitis, encephalomyelitis, radiculomyelitis, peripheral neuropathy
Acrodermatitis chronic atrophicans
Lyme arthritis

Question 9

Prognosis for lyme disease

Answer 9

Tick removed - most don’t need antibiotics
Most people recover with Abx, may take several months after completing antibiotics