It’s that time of year again. As the Lyme endemic regions of the United States shake off the winter, people start to wander outside and into the Emergency Department with tick bites. This summary is meant to serve as a quick review of Lyme Disease based on current recommendations from the CDC and IDSA. At the end of this evidence based review, you will find quick reference summary cards (good board review material).
BLACKLEGGED DEER TICK (Ixodes scapularis)
Lyme Disease Map: 2017
CDC/IDSA Public Health Lyme Disease Facts
- The CDC estimates there are roughly 300,000 cases of Lyme disease in the US every year. However, only 30,000 are actually reported.
- Cases of vector borne diseases from ticks and mosquitos have tripled since 2004.
- The cost of Lyme disease testing alone is estimated at $492 million per year
- Lyme disease is caused by the bacteria Borrelia burgdorferi
- Lyme disease is only transmitted to humans when they are bitten by an infected tick
- To infect its host, a tick typically must be attached to the skin for at least 36 hours
- Most cases of Lyme disease occur in late spring and early summer
- About 70-80% of people infected develop the rash, which shows up several days to weeks after the tick bite.
- It may take 4-6 weeks for the body to make antibodies against Borrelia burgdorferi and therefore show up in a positive blood test. That is why patients with the Lyme rash usually have a negative blood test and diagnosis is based on the characteristic appearance of the rash. Patients with other clinical manifestations such as Lyme arthritis will usually have a blood test. Anyone who has symptoms for longer than six weeks and who has never been treated with antibiotics is unlikely to have Lyme disease if the blood test is negative.
- The best treatment for Lyme disease is prevention: Be cautious when walking in the woods, avoiding bushy and grassy areas. Wear long pants and long-sleeved shirts and wear insect repellent containing DEET on exposed skin. After walking in wooded areas, thoroughly check the skin for the poppy-seed sized ticks, paying particular attention to the scalp, armpits and groin. If you find a tick, carefully remove it with tweezers.
Protect yourself (patient education pearls)
- Use Environmental Protection Agency (EPA)- registered insect repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol, or 2-undecanone.
- Wear clothing treated with permethrin.
- Shower as soon as possible after spending time outdoors.
- Check for ticks daily. Ticks can hide under the armpits, behind the knees, in the hair, and in the groin.
- Tumble clothes in a dryer on high heat for 10 minutes to kill ticks on dry clothing after you come indoors. If the clothes are damp, additional time may be needed.
Find a printable education handout from the CDC here
How to remove a tick (CDC recommendations)
- Use fine-tipped tweezers to grasp the tick as close to the skin’s surface as possible.
- Pull upward with steady, even pressure.
- Don’t twist or jerk the tick; this can cause the mouth-parts to break off and remain in the skin.
- If this happens, remove the mouth-parts with tweezers.
- If you are unable to remove the mouth easily with clean tweezers, leave it alone and let the skin heal. In most cases, they will fall out in a few days.
- After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol or soap and water.
- Never crush a tick with your fingers.
- Dispose of a live tick by putting it in alcohol, placing it in a sealed bag/container, wrapping it tightly in tape, or flushing it down the toilet.
- Avoid home remedies such as “painting” the tick with nail polish or petroleum jelly, using head to make the tick detach from the skin.
- The main goal is to remove the tick as soon as possible. Do not wait for it to detach.
Post-Exposure Prophylaxis
The CDC and the Infectious Disease Society of America (IDSA) does not generally recommend antimicrobial prophylaxis for prevention of Lyme disease after a recognized tick bite. However, in highly endemic areas, a single dose of doxycycline may be offered to adult patients (200 mg) who are not pregnant and to children older than 8 years of age (4 mg/kg up to a maximum dose of 200 mg).1,2
To consider prophylaxis, all of the following circumstances must exist:
- Doxycycline is not contraindicated
- The attached tick can be identified as an adult or nymphal scapularistick
- The estimated time of attachment is ≥ 36 hours based on the degree of tick engorgement with blood or likely time of exposure to the tick.
- Prophylaxis can be started within 72 h of tick removal
- Lyme disease is common in the county or state where the patient lives or has recently traveled (i.e., CT, DE, MA, MD, ME, MN, NH, NJ, NY, PA, RI, VA, VT, WI)
Prophylaxis following a tick bite is not recommended as a means to prevent anaplasmosis, babesiosis, ehrlichiosis, Rocky Mountain spotted fever, or other rickettsial diseases.
Is Doxycycline really contraindicated in children < 8 years old?
The IDSA last published recommendations on the treatment of Lyme disease in 2006. At that time, Doxycycline was still recommended to be contraindicated in children <8 years old. While teeth discoloration has been well established with tetracyclines, this dogma was originally described in the 1940’s, prior to Doxycycline hitting the market in the late 1960’s. Doxycycline has less affinity for calcium than other tetracyclines, and has not been shows to cause tooth staining.7 The IDSA panel last met in 2009 to review the 2006 Lyme Disease treatment guidelines. While they suggested some minor verbiage changes to future publications, there was not enough discrepancies between the 2006 published guidelines and current literature to warrant a revised publication at that time. That being said, their specific stance on the use of prophylaxis with Doxycycline in pediatric patients under the age of 8 has yet to change on paper. In fact, in my review of the literature, I cannot find any specific society guidelines recommending Doxycycline for Lyme prophylaxis in children less than 8 years of age. Further, they maintain that there have been no clinical trials of Doxycycline for pediatric patients with Lyme disease, but it is reasonable to extrapolate from the adult data in the recommendation.2
In 2013, the CDC conducted a retrospective review of children in a community with high rates of RMSF.8They compared children who had received doxycycline before the age of 8 years in the treatment of suspected RMSF with children who had never received doxycycline. Dentists who were blinded to exposure status, performed quantitative and qualitative evaluations of tooth color and enamel hypoplasia. The study showed no evidence of subjective tetracycline-like staining, no difference in the rate of enamel defects, and no difference in tooth shade between the children who had received doxycycline and those who had not. This study provides the best evidence to date that short courses of doxycycline do not cause dental staining when given to children under the age of 8 years.
Further, there are numerous recommendations from both the CDC, the American Academy of Pediatrics and the IDSA favoring the use of Doxycycline for children of all ages in the treatment of many other tickborne diseases.1,2,3,4,5 Recent literature has shown Doxycycline to be safe in children of all ages for up to 21 days of treatment and this is described in Section 4 of the 2018 AAP Red Book 2018 update.3
Doxycycline is, however, contraindicated in pregnant and lactating women.
What if you can’t use Doxycycline for prophylaxis?
Answer….then don’t use anything. You read that right. The risk of Lyme disease is only 1-3% after being bitten by a tick, even in highly endemic areas.6 The IDSA does not recommend the substitution of Amoxicillin if Doxycycline is contraindicated.2 There is no data to support the benefit of a single dose of Amoxicillin. A longer course regimen is more likely have a higher rate of adverse effects than would offer the benefit of prophylaxis. Given the excellent efficacy of treatment of Lyme disease, education on signs and symptoms of Lyme Disease (EM rash or flu-like symptoms) and recommend home monitoring for 30 days is likely to be more beneficial.
Is there a Lyme Disease Vaccine?
There was, but the vaccine manufacturer discontinued production in 2002, citing insufficient demand. Protection from prior vaccines are unlikely to offer protection against Lyme disease today, as efficacy diminishes over time.
How is Lyme Disease Diagnosed?
Early Lyme disease is mainly diagnosed by clinical symptoms (EM rash or flu-like symptoms) developing 3-30 days after a possible blacklegged tick bite. Remember, serology takes 4-6 weeks to turn positive, and unlikely to be of clinical utility at this stage. For patients who present with symptoms of late Lyme disease, the Two-tier testing decision is recommended by the CDC for proper diagnosis. The two steps of Lyme disease testing are designed to be done together. The CDC does not recommend skipping the first test and just doing the Western blot. Doing so will increase the frequency of false positive results and may lead to misdiagnosis and improper treatment.
Just a reminder…the Jarisch-Herxheimer reaction is a thing
- Fever, headache, myalgia and a worsening clinical picture lasting <24 h after antibiotic therapy is initiated
- NSAID’s should be started and antimicrobial agent should be continued.3
ISDA 2009 Panel Pearls
Should Ticks be tested for tickborne infectious agents?
Short answer is…..NO
What if I can’t tell if it’s an EM rash or a community-acquired bacterial cellulitis?
“A reasonable approach is to treat with either cefuroxime axetil or Augmentin (500 mg tid in adults, or 50 mg/kg/day divided tid in children) as they are generally effective against both types of infections. Consider Doxycycline if community rates of MRSA are high.First-generation cephalosporins, fluoroquinolones, carbapenems, vancomycin, metronidazole, tinidazole, ketolides, isoniazid, trimethoprim-sulfamethoxazole, fluconazole, benzathine penicillin G and combinations of antimicrobials are ineffective in the treatment of Lyme disease.”
Should I be concerned about co-infections with Lyme Disease?
“Coinfection with B. microti or A. phagocytophilum or both may occur in patients with early Lyme disease (usually in patients with erythema migrans) in geographic areas where these pathogens are endemic. Coinfection should be considered in patients who present with more severe initial symptoms than are commonly observed with Lyme disease alone, especially in those who have high-grade fever for >48 hours, despite receiving antibiotic therapy appropriate for Lyme disease, or who have unexplained leukopenia, thrombocytopenia, or anemia, abnormal hepatic transaminases (AST and ALT), lactate dehydrogenase, or bilirubin. Coinfection should also be considered in the situation in which there has been resolution of the erythema migrans skin lesion, but either no improvement or worsening of viral infection-like symptoms.”
Can oral treatment be used for Early Neuroleptic Lyme?
“For adult patients with early Lyme disease and the acute neurologic manifestations of meningitis or radiculopathy, Ceftriaxone 2 g q24h x 14 days (range 10–28 days) is recommended. However, consideration should be given to the emerging data supporting the use of oral Doxycyline as first line therapy in selected patients with neurologic manifestations of Lyme disease, such as those with hypersensitivity to beta lactam antibiotics. Cefotaxime (2 g IV q8 hours) or Penicillin G (18–24 million U/day for patients with normal renal function, divided into doses q4h), may be a satisfactory alternative or patients who are intolerant of ß-lactam antibiotics. Increasing evidence indicates that doxycycline (200–400 mg per day in 2 divided doses orally for 10–28 days) may be adequate. Doxycycline is well absorbed orally; thus, IV administration should rarely be needed. For children, Ceftriaxone (50–75 mg/kg per day) in a single daily IV dose (maximum, 2 g) is recommended. An alternative is Cefotaxime (150–200 mg/kg per day) divided into 3-4 IV doses/day (maximum, 6 g per day) or penicillin G (200,000– 400,000 units/kg per day; maximum, 18–24 million U per day) divided into doses given IV q4 h for those with normal renal function. Children >8 years of age have also been successfully treated with oral Doxycycline at a dosage of 4–8 mg/kg per day in 2 divided doses (maximum, 100–200 mg per dose).”
Can Lyme Disease cause increased intracranial pressure?
“The presence of either papilledema or sixth cranial nerve palsy may indicate the presence of increased intracranial pressure. Although elevated intracranial pressure typically responds to systemic antibiotic therapy, other measures to lower pressure, such as serial lumbar punctures and use of corticosteroids or acetazolamide, may be considered in individual cases. CSF shunting was thought to be necessary in one patient to control increased intracranial pressure that appeared to be causing or contributing to loss of vision.”
Do patients with CN 7 palsy require lumbar puncture?
“Cranial nerve palsies in patients with Lyme disease are often associated with a lymphocytic CSF pleocytosis, with or without symptoms of meningitis. Panel members differed in their approach to the neurologic evaluation of patients with Lyme disease–associated seventh cranial nerve palsy. Some perform a CSF examination on all such patients. Others do not because of the good clinical response with orally administered antibiotics (even in the presence of CSF pleocytosis) and the absence of evidence of recurrent CNS disease in these patients. There was agreement that lumbar puncture is indicated for those in whom there is strong clinical suspicion of CNS involvement (e.g., severe or prolonged headache or nuchal rigidity). Patients with normal CSF examination findings and those for whom CSF examination is deemed unnecessary because of lack of clinical signs of meningitis may be treated with a 14-day course (range, 14–21 days) of the same antibiotics used for patients with erythema migrans.”
Does Lyme Carditis require hospitalization?
“Patients with atrioventricular heart block and/or myopericarditis associated with early Lyme disease may be treated with either oral or parenteral antibiotic therapy for 14 days (range, 14-21 days). Hospitalization and continuous monitoring are advisable for symptomatic patients, such as those with syncope, dyspnea, or chest pain. It is also recommended for patients with second- or third-degree atrioventricular block, as well as for those with first-degree heart block when the PR interval is prolonged to >300 milliseconds, because the degree of block may fluctuate and worsen very rapidly in such patients. For hospitalized patients, a parenteral antibiotic, such as ceftriaxone, is recommended as initial treatment of hospitalized patients.”
What is post-Lyme disease syndrome?
“To date, there is no convincing biologic evidence for the existence of symptomatic chronic B. burgdorferi infection among patients after receipt of recommended treatment regimens for Lyme disease and there is no well-accepted definition of post–Lyme disease syndrome. This has contributed to confusion and controversy and to a lack of firm data on its incidence, prevalence, and pathogenesis. When laboratory testing is done to support the original diagnosis of Lyme disease, it is essential that it be performed by well-qualified and reputable laboratories that use recommended and appropriately validated testing methods and interpretive criteria. Unvalidated test methods (such as urine antigen tests or blood microscopy for Borrelia species) should not be used. Antibiotic therapy has not proven to be useful and is not recommended for patients with chronic (>6 months) subjective symptoms after recommended treatment regimens for Lyme disease.”
Chart Summaries
References
- “Tick Bite Prophylaxis | Tick-Borne Diseases | Ticks | CDC.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 10 Jan. 2019, cdc.gov/ticks/tickbornediseases/tick-bite-prophylaxis.html.
- Wormser, G P, and R J Dattwyler. “Tick Bite Prophylaxis | Tick-Borne Diseases | Ticks | CDC.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 21 Aug. 2006, www.cdc.gov/ticks/tickbornediseases/tick-bite-prophylaxis.html.
- American Academy of Pediatrics. Lyme disease (Lyme borreliosis, Borrelia burgdorferi infection). In: Kimberlin DW, Brady MT, Jackson M, Long SS, eds. Red Book: 2018 Report of the Committee on Infectious Diseases, 31st edn. Elk Grove Village: American Academy of Pediatrics, 2018:515-523
- Todd SR, Dahlgren FS, et al,. No visible dental staining in children treated with doxycycline for suspected Rocky Mountain Spotted Fever. J Pediatr. 2015 May;166(5):1246-51. doi: 10.1016/j.jpeds.2015.02.015. Epub 2015 Mar 17.
- PöyhönenH, Mirka NurmiM, et al,. Dental staining after doxycycline use in children. J Antimicrob Chemother.2017 Oct; 72(10): 2887–2890. doi: 1093/jac/dkx245
- Shapiro ED. Borrelia burgdorgeri (Lyme Disease). Pediatr Rev. 2014 Dec; 35(12):500-509.
- HM Biggs et al. Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever and other spotted fever group Rickettsioses, Ehrlichioses, and Anaplasmosis – United States. MMWR Recomm Rep 2016; 65:1.
- Biggs HM, Behravesh CB, Bradley KK, et al. Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis — United States. MMWR Recomm Rep 2016;65(No. RR-2):1–44. DOI: http://dx.doi.org/10.15585/mmwr.rr6502a1External
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