Lyme Disease

Lyme disease is caused by the __________ _______ ________ and is transmitted to humans through the bite of infected blacklegged _______

bacteria borrelia burgdorferi, ticks

Lyme disease is the ______ ______ tick-borne illness in the US

most common

Who does lyme disease affect more?

males, caucasians

96% of the cases in the US occur in the __________, __________, _________

northeast, wisconsin, minnesota

What is the shape of the borrelia burgdorferi bacteria?

spirochete

What is the name of the infected blacklegged ticks that serve as the vector for transmission?

ixodes scapularis, ixodes pacificus

What animals serve as the reservoir for blacklegged ticks?

mice, deer, other small animals

How do humans get infection by the tick?

tick transmits the spirochete into saliva tissue while feeding

Lyme disease rarely transmitted unless tick attached to and feeding on a human hose for _______-______ hours

36-48+

Transmission most commonly occurs during the __________ stage

nymph

What ticks are at higher risk for transmission?

engorged ticks

Humans are a ________ ______ ______

dead end host

When are tick bites more common?

late spring/early summer

When do tick bite symptoms typically manifest?

3-30 days but can be longer

How is lyme disease NOT transmitted?

human contact, mosquitos, flies, fleas or lice, eating squirrel or deer meat, airborne or water contact

What are the 3 stages of lyme disease?

early localized, early disseminated, late disseminated

What is the early localized stage of lyme disease?

skin lesions in days to weeks

What is the early disseminated stage of lyme disease?

multiple lesions, systemic symptoms, weeks to months later

What is the late disseminated stage of lyme disease?

arthritis, months to years later

The early localized infection usually appears _______-________ days after the tick bite

3-30

What is the most common finding of the early localized infection?

erythema migrans, aka a migrating redness rash

True or False: every patient that has been infected by a tick develops a rash

false

Typically the rash starts at the ________ of the tick bite and ______ ______

site, expands slowly

Some patients develop a central clearing with a ________ _______

bullseye pattern

What are non-specific symptoms of early localized infection?

fatigue, malaise, fever, mild headache, lymphadenopathy, myalgia, arthralgia

What is the CDC definition of EM?

lesions is >= 5 cm in diameter expanding over days to weeks

The rash is typically ________ _______ but it can ________ and feel ________

not painful, itch, feel warm

What happens if the localized infection is untreated?

early disseminated infection can occur

Early disseminated infections occur ______ to ______ after infection and can result in patients have _______ _______ ______

days, weeks, multiple EM lesions

What occurs in early disseminated infection?

the spirochete disseminates throughout the body

What are extracutaneous manifestations that are developed in early disseminated infection?

neurologic lyme disease, cardiac findings, joint involvement

What is the most common nerve palsy associated with lyme disease?

bell's palsy

Bell's palsy + ________ = very suspicious for lyme disease

fever

What else is very suspicious for lyme disease?

any child with bell's palsy

Lyme disease can also affect ________ causing ________ _________

CN2, disc edema

What are other neurologic manifestations of lyme disease?

tingling, numbness, meningitis, acute febrile polyneuritis

Late disseminated lyme disease occurs _______ to ________ later

months, years

What is the most common late disseminated manifestation?

lyme arthritis

What are the presentations of lyme arthritis?

migratory monoarthritis, asymmetric oligoarthritis, intermittent marked swelling with slight pain of large weight-bearing joints

Where the swelling most commonly seen?

knee

What are chronic neurologic manifestations that can develop during the late disseminated phase?

encephalopathy, memory loss, difficulty concentrating, paresthesia

What are ocular manifestations of lyme disease?

conjunctivitis

What are EARLY ocular manifestations of lyme disease?

follicular conjunctivitis, episcleritis, periorbital edema

What are LATE ocular manifestations of lyme disease?

CN palsies, granulomatous uveitis, disc edema, keratitis, pars planitis, choroiditis, retinal vasculitis

Lyme disease does not require _______ _______

serologic tests

True or False: the absence of an EM lesion or tick bite does not rule out lyme disease

true

When do we perform serologic testing for lyme disease?

recent travel to an area endemic for lyme disease, risk of exposure to ticks, symptoms

Does the symptoms criteria for serologic testing include rashes?

no

Ig____ antibodies are detected before Ig____ antibodies

M, G

What are antibody screening tests for lyme disease?

ELISA, IFA

What are secondary tests for lyme disease?

western blot

If IFA or ELISA are negative:

it is likely not lyme disease but you could have potentially tested too early

If the ELISA or IFA are positive but the western blot is negative:

you have a false positive and it is not lyme disease

If the ELISA or IFA are positive and the western blot is positive:

it is lyme disease

It is rare to test positive if the patient still has a _______ ______

EM rash

These tests have ______ specificity for _______ lyme disease

poor, early

How do we treat lyme disease?

100 mg doxycyline BID or 500 mg amoxicillin TID or 500 mg cefuroxime BID for 10-14 days

How do we treat lyme disease if the pt has neurologic symptoms?

100 mg doxycyline BID for 10-14 days or IV ceftriaxone

How do we treat late lyme disease with lyme arthritis?

doxycycline, amoxicillin, or cefuroxime for 28 days

How do you treat late lyme disease with lyme arthritis if patient are still symptomatic?

re-treat with another 28 days of oral antibiotics or IV ceftriaxone for 14-28 days

Lingering symptoms may be due __________ rather than __________

inflammation, infection

If still symptomatic after 2nd treatment:

use NSAIDs, corticosteroids, DMARDs

How do we treat neurologic manifestations in late stage lyme disease?

doxycycline or IV ceftriaxone

What is post lyme disease syndrome/chronic lyme disease?

symptoms persist for months/years even after treatment

Post lyme disease syndrome/chronic lyme disease can last ______ months to ________ years

6, 5+

What are preventative measures?

reduction of tick habitat, light colored clothing with permethrin sprays, long sleeved shirts and pants tucked into socks, DEET insect repellent, bath or shower within 2 hours of exposure, monitor gear

What percent should the DEET insect repellent be?

>= 20%

How do you monitor gear?

tumble on high in dryer for 10 min

How do you remove a tick?

grasp tick as close to skin as possible and pull tick away from body with smooth motion

After removing the tick, what should you do?

clean the area and hands with soap and water, iodine scrub or rubbing alcohol

How do you dispose of the tick?

submersing it in alcohol, placed in seal bag, wrapping it tightly in tape, or flushing down the toilet

If all the requirements are true, medical prophylaxis can be offered. What is the dose?

single dose of 200 mg doxycycline