Lyme Disease Flashcards
Pathogens of Lyme Disease
- An infection caused by Borrelia burgdorferi sensu lato (Gram negative spirochaete bacterium)
= B burgdorferi sensu stricto (US, arthritis)
= Borrelia afzelii (Europe, cutaneous)
= Borrelia garinii (Europe, neurotropic)
How is Lyme Disease transmitted?
Bite of an infected tick (Ixodes ricinus in UK and Europe, Ixodes persulcatus in Asia)
Another term for Lyme Disease
Lyme borreliosis
Risk Factors for Lyme Disease
-Endemic area
-Tick infection prevalence
-Occupation: forestry
-Leisure: Hunting, hiking
Stage 1 (days to weeks) common clinical features
-Erythema migrans (flu-like symptoms as well US)
-Borrelial Lymphocytoma (dense polyclonal lymphocyte infiltration, often on nipple in adults or earlobe in children)
Stage 2 (weeks to months) common clinical features
-Disseminated infection, systemic symptoms: Lyme neuroborreliosis
=Acute neurological involvement, often lymphocytic meningitis, cranial neuritis or radiculoneuritis
-Carditis
=First to third degree atrioventricular block
Stage 3 (months to years) common clinical symptoms
-Lyme arthritis
=In one or few joints, most commonly within knee with minimal (if any) systemic symptoms
-Acrodermatitis chronica atrophicans
=Oedema (purplish), atrophy of the skin and local peripheral sensory neuritis
Overall clinical Lyme disease
-Early Lyme disease
– rash/erythema migrans/flu-like symptoms
- Early disseminated Lyme disease
= meningitis, carditis, uveitis
- Late Lyme disease
= joints/arthritis, neurological, skin/ACA
Serology testing for Lyme disease
- Screen blood with sensitive EIA
- Confirm with sensitive and specific IgG Immunoblot (IB) and IgM immunoblot
- EIA test for CSF/serum pair for neuroborreliosis
-Protocol
– EIA positive or equivocal referred for IB
What is diagnosed using Borrelia PCR?
-Acute neuroborreliosis
-Lyme arthritis
When not to test with serology
-Following tick bite with nil associated symptoms
-Classic EM
-As a test of cure/ seroconversion
-Less than 4 weeks following exposure
When should you test with serology?
-Repeat sampling if initial ELISA taken <10 weeks post onset of symptoms
-Early disseminated/ late lyme disease
-High epidemiological / occupational risk and non-specific symptoms
-Pre test and certainly pre-treatment counselling
-If significant clinical concern then treat whilst awaiting serology results
Initial management of Lyme disease
-Clear benefit for early diagnosis and treatment =more likely to be curative
=reduce ‘post Lyme disease syndrome’
=cost effective
-Focal signs = treatment and discussion as necessary
-Urgent specialty assessment for CNS/ cardiac/ eye
-Children (<18y) generally discuss with specialist
Erythema migrans and/or non-focal symptoms treatment
-Doxycycline (21 days)
-Amoxicillin (21 days)
-Azithromycin (17 d)
Lyme disease affecting cranial nerves or peripheral NS treatment
-Doxy (21d)
-Amox (21d)
