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Lyme Disease

Neda Frayha, MD, Mizuho Morrison, DO, and Heidi James, MD

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Lyme disease is the most common tick-borne illness in North America. Infections peak in the spring and summer months. Preventing tick-bites and checking oneself for ticks after time spent outdoors in endemic areas is key. Prophylaxis should be given (doxcycyline 200 mg x 1 dose) if patient had a tick attached for more than 36 hours, and you can give the dose within 72 hours of the tick coming off.  If untreated, Lyme progresses through three stages: (1) early localized, (2) early disseminated, and (3) late. Each of these is has its own complications and treatment. Current research does not support the use of long-term antibiotics to treat the symptom constellation frequently referred to as Chronic Lyme Disease.

  • Lyme disease is the most commonly reported vector-borne illness. It is carried by the spirochete borrelia burgdoferi via the ixodes scapularis tick bite.

  • Because patients often never remember the bite, prevention is key: 20-30% DEET, treat clothing with 0.5% permethrin cream and cover your skin when outdoors.

  • If a tick was attached for more than 36 hours and you see the patient within 72 hours (3 days) of the tick being removed, a single dose of doxycycline 200mg is the suggested prophylaxis.

  • Lyme disease presents as early localized, early disseminated, late. Each is treated similarly (doxycycline for 2-3 weeks), though complications involving the heart and brain generally require hospital admission and IV doxycycline.

  • Post-treatment Lyme disease syndrome (aka: chronic Lyme disease) is more likely an autoimmune process and long-term antibiotics have not been shown to be effective.


  • Lyme disease is now the most commonly reported vector-borne illness.

    • Over 30,000 cases per year

    • Caused by the spirochete borrelia burgdoferi infecting people via a tick bite

    • Vector is the Ixodes scapularis tick: larva → nymph (poppy seed) → adults (need a blood meal to advance to next stage of development)

    • Affects people of any age group but tends to be bimodal (children 5-15, adults 40-50)

    • More common in spring and summer time

    • Most common in US Northeast

  • Most patients never remember the bite which is why it is so important to talk about prevention strategies.

    • Insect repellant with 20-30% DEET covering all uncovered areas of skin

    • Treat clothing with 0.5% permetherin cream

    • Tuck pant legs into your socks

  • What do you do to check to see if a tick has attached? Check everywhere! Areas under arms, around waist, ears, scalp, bellybutton and between your legs. May look like a mole or freckle.  You can also take  a hot bath within two hours of being outdoors to prevent the tick from attaching any longer.

  • How does the duration of tick attachment affect your risk of infection? The longer the tick is attached, the more at risk of infection.

    • 500 patients with ticks attached for greater than 36 hours received either a single dose of doxycycline 200mg or placebo pill within 72 hours of the tick being removed. With 6 week follow-up, there was a statistically significant decrease in Lyme infection in those who received prophylaxis.

    • Nadelman RB et. al. Prophylaxis with single-dose doxycycline for the prevention of Lyme disease after an Ixodes scapularis tick bite. N Engl J Med. 2001 Jul 12;345(2):79-84. PMID: 11450675.

  • Stages of Lyme disease and treatment:

    • Early localized - appearance of erythema migrans (bulls eye lesion, non-pruritic, 70-80% of Lyme disease, shows up anywhere from 3 to 30 days after initial bite) + constitutional symptoms (fatigue, malaise)

      • Tx: doxycycline 100mg PO BID for 14-21 days

    • Early disseminated - up to 10 months after the tick bite, may have multiple erythema migrans lesions, bilateral Bell’s palsy (15% of patients), meningitis, encephalitis, AV block (1st to 3rd degree), myopericarditis.

      • Tx: doxycycline 100mg PO BID for 14-21 days

      • Tx if cardiac findings require inpatient management for close monitoring

    • Late - may occur in up to 60% of untreated patients within months of being bitten. May see arthritis (usually large joints), encephalopathy, paresthesias and radicular pain

      • Tx: doxycycline 100mg PO BID for 28 days

      • Neurologic symptoms may require inpatient treatment

    • Alternative dosing if allergic to doxycycline, pregnant or children under 8: amoxicillin 500mg TID or cefuroxime 500mg BID.  These agents haven’t been studied for use as prophylaxis so there’s really no alternative if doxycycline is contraindicated.

  • Diagnostic testing:

    • CDC recommends starting with an ELISA or immunofluorescent assay followed by a Western blot.

      • If ELISA is negative → done

      • If ELISA positive or equivocal → test for IgG or IgM with western blot

    • Serologies are warranted if you are traveling or live in an endemic area and have a symptom consistent with early disseminated disease or late Lyme disease

    • Serologies are NOT warranted if clinically you have erythema migrans with clear exposure to tick or you’re screening an asymptomatic person or the person presents with vague symptoms (fatigue, malaise) for years.

  • Chronic Lyme disease (aka: post-treatment Lyme disease syndrome): symptoms that linger after infection with Lyme disease

    • The idea of these symptoms being caused by chronic infection are not supported by major organizations like the IDSA, AAN or International Lyme Disease Group because they do not find evidence to support the idea of chronic infection from the spirochete.

    • Several separate double-blinded placebo-controlled randomized control trials show little to no benefit of long-term antibiotics in patients with symptoms.

    • It is thought to be an autoimmune process.

    • While doctors may try many different treatments, the current recommendation is to seek other causes for these symptoms.

    • Many cases resolve after 6-12 months.

Judith H. -

Hi there! A GP on the West coast here. My husband and I are hikers and have had numerous tick bites (we have a different tick here than the one mentioned in your podcast- Ixodes pacificus). Most recently, last spring, hubby got a tick bite but he caught it and we took it out within 10 hours of when it latched on. Furthermore, it wasn't swollen with blood. Based on the textbook teaching, we felt free and clear to chuck the tick down the toilet. Eight hours later, hubby woke up with a classic bulls eye rash (I could attach a photo, but if it's basically identical to your cartoon drawing). About 4 hours later he was taking his 1st dose of doxycycline, and he was actually seen by an infectious disease specialist the following day. This fellow said that as far as he was concerned, the tick had transmitted the Lyme pathogen to hubby- the tick hadn't read the text book. Also interestingly, the serology test was negative (both baseline and 4 weeks later).

Heidi J., MD -

Wow! That's quite the hiking adventure! Mother Nature sure does not read textbooks.
I'm passing your comment along to Neda in case she has any insight.
Thanks for sharing,

Heidi J., MD -

Just chatted with Neda; we're both amazed! Crazy tick ;) Please k eep us updated if there are any further developments.

Judith H. -

There better NOT be any further developments! :)

Heidi J., MD -


Jerica W., CRNP -

Just a question about what are the current recommendations for treating patients who have removed ticks from themselves and sent it to a testing facility, where the tick has Borrelia burgdorferi. Do we treat based off the test result or wait for the patient to be symptomatic? Typically it takes 4-5 days for the patients to send the tick out and get results back.

Neda F., MD -

Hi Jerica. The new IDSA treatment guidelines for Lyme are supposed to come out this fall. In the meantime, based on the 2006 recommendations, a few thoughts. (1) The patient may be a good candidate for a one-time prophylactic dose of doxycycline 200mg - if the tick is I scapularis, it's been attached for >36 hours, and you can give doxy within 72 hours of removing the tick. (2) The 2006 recommendations don't recommend routinely sending ticks for testing, unless it's part of a research study. And finally, (3) "Persons who have removed attached ticks from themselves (including those who have received antibiotic prophylaxis) should be monitored closely for signs and symptoms of tickborne diseases for up to 30 days; in particular, they should be monitored for the development of an expanding skin lesion at the site of the tick bite (erythema migrans) that may suggest Lyme disease. Persons who develop a skin lesion or viral infection–like illness within 1 month after removing an attached tick should promptly seek medical attention to assess the possibility of having acquired a tickborne infection." Hope this helps! - Neda

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Antibiotics in the Lyme-Light Full episode audio for MD edition 170:54 min - 80 MB - M4AHippo Primary Care RAP April 2017 Summary 1 MB - PDF