Lyme's
Disease
Ticks harbor many infectious diseases. Ticks typically lie
on shrubbery and will crawl onto people. People infected are
usually bitten by the nymph stage, which can be small.
Rarely an adult tick will cause problem. Lyme disease incidence
peaks in June and July, which corresponds to when the nymph
tick is most active in May, and June.
Lyme Disease Stage
1:
Fever, muscle aches, flu-like symptoms, enlarged lymph nodes.
Erythema Migrams
- as symptomatic 5-20cm round or oral rash with central clearing
occurs <50% of the time
- occurs 7-10 days after bite at bite site (usually the margins
of underwear will stop the ticks ascend up a leg.
- 90% of Lyme patients have erythema migrams, less than ½
are recognized
- diagnosis is clinical. Serology is often negative. This
is the best opportunity for diagnosis and treatment. (Do not
miss this window of opportunity)
- organisms can be cultured from the leading edge of rash,
but this requires special media that is not readily available.
Stage 2: Acute Disseminated Phase
1-secondary skin lesions
2-cardiac disorders
3-CNS disorders
4-neurological diseases
Skin Lesions
- look like red spots
-10-20% of time in untreated people
-usually smaller and less migrations may occur anywhere in
the body
Neurologic Lesions
- 15-20% of untreated
-Facial nerve palsy not common
-"Aseptic" meningitis
- headache
-photophobia, neck, stiffness
-CSF fluid (pleocytosis - 10-100) and elevated protein
-chronic confusional state
-leukoencephalitis very rare, similar to multiple sclerosis
-some reversible CT scan abnormalities
Cardiac Lesions
- 8-10% of untreated
-1st-3rd degree heart block
-myocarditis or pericarditis by EKG (60%)
-mild left ventricular dysfunction (50%)
-may require hospitalization for cardiac pacing or observation
-most common cause of death in Lyme Disease
Stage 3: Chronic Widespread Arthritis (60%)
-recruitment a symptomatic pain
-usually 1 joint, lasting about 8 days
-predispostion forknee>shoulder>elbow>TMJ
-Inflammatory synorial fluid, organisms may be detected
-becomes chronic and destructive in 10%
-people with haplotype DRA may be predisposed to developing
arthritis
Diagnosis
- Erythema Migrans rash
- pathognomatic for Lyme disease
If no skin lesions:
-thorough examination
-check if history consistent with tick bite and get lab confirmation
Lab Studies
- lgM presents 2 wks, peaks 3-4 wks then declines
- lgg presents 4-6 wks, peaks 8 wks, then may be elevated
for years
Early Removal of Tick (is best)
-clean wound
-meticulous search for other ticks which may be very small
-follow-up for fever, headache and rash
Arthropod Avoidance
DEET - effective against mosquitoes, not as good against
ticks
Permethrin - very effective -spray lasts 1 or 2 washings
-soaking clothing in solution 1.5cc of 13% solution/L lasts
50 washings
-strong smell but disappears when dried
Vaccine (no longer available)
- from protein (recombinent vaccines)
- effectiveness 49% after 2 injections, 76% after 3 injections
- duration of protection unknown
- vaccinations in outer membrane in Europe, so European Lyme
Disease is not prevented
- vaccinees will not develop erythema migrans rash if infected
Babesiosis
- concurrent parasite = with Lyme Disease
-same distribution
-co-infected patients have headache, fever, chills, anorexia,
and conjunctivitis symptoms for 3 months or longer
- also Ehrlichosis also has similar distribution as Lyme Disease
Treatment of Lyme Disease
Primary (Stage 1)
Infections where erythema chronicum migrans is seen, can
be treated with one of the following:
- Doxycycline 100mg po BID x 10-21days
- Amoxil 500mg po BID x 10-21 days
- Cefuroxime 50mg po BID x 10-21 days
- Zithromax 500mg po BID then 250mg po od x 4 (12 pack)
Arthritis - treat with one of the following:
- Doxycycline 100mg po BID x 30 days
- Amoxil 500mg TID x 30 days
- Ceftriaxone 2g IV q4h x 14-21 days
- Pan G 4million units IV q4h x 14-21 days
Isolate facial palsy (where Lyme disease suspected)
- Doxycycline 100mg po BID x 30 days
- Amoxil 500mg TID x 30 days
Other neurologic SX:
- Ceftriaxone 2g IV od x 14-21 days
- Pan G 4million units q4h x 14-21 days
References:
New Front Against Lyme Disease
www.gene.com/ae/WN/SU/front_against_lyme_disease.html
Centre for Disease Control http://www.cdc.gov/ncidod/diseases/submenus/sub_lyme.htm
European Union Concerned in Action on
Lyme Borreliosis (EUCACB) www.dis.strath.ac.uk/vie/lymeEU/
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