- Posted on: Oct 7 2020
What is Lyme Disease?
Lyme disease is a tick-borne disease caused by the bacteria Borrelia burgdorferi. It is spread by the vector Ixodes Scapularis (deer tick). Lyme disease occurs most commonly in Spring and Summer in the Northeast, Midwest, and Mid-Atlantic regions of the United States. Transmission is unlikely to occur if tick attachment is <24-48 hours and VERY likely if the attachment is >72 hours.
General infection occurs with 36-48 hours of attachment.
What are the signs and symptoms of Lyme Disease?
There are 3 phases of Lyme disease:
- Phase 1 (early localized, 7-14 days)
- Erythema chronicum migrans (ECM) will affect 30%-80% of patients and presents with an expanding, warm, annular erythematous rash with a central clearing, also referred to as a “bulls-eye” rash. During phase 1 Lyme titer will be negative. It will be positive in stages 2 and 3.
- Nonspecific symptoms: fatigue, myalgia, malaise, lethargy, HA, arthralgia, and regional lymphadenopathy.
- *It is hard to diagnose Lyme in this stage because the symptoms are so vague
- Phase 2 (early disseminated, weeks to months)
- MSK affects 60% of patients, especially in the large joints, most commonly the knees
- Neuro affects 15% of patients causing lymphocytic meningitis, CN7 palsy (bell’s palsy), cerebral ataxia, radiculopathy, encephalitis, lymphocytic meningitis
- Cardiac affects 1% of patients causing heart blocks, cardiomyopathy, and myopericarditis.
- *AV block is the most common manifestation of Lyme carditis.
- Phase 3 (late disease, months to years)
- Arthritis affects 60% of patients most commonly in the knees, persistent synovitis.
- Neurologic symptoms like bell’s palsy, cerebral ataxia, radiculopathy, encephalitis, lymphocytic meningitis
What are the differential diagnoses of Lyme Disease?
- Rheumatoid Arthritis
- Systemic lupus erythematosus
- Gonococcal arthritis
How to diagnose Lyme Disease?
- Clinical, especially in early Lyme disease. There wil be a presence of the ECM rash, history of a tick bite, and/or arthritis.
- Serologic testing, Elisa followed by the Western Blot if Elisa is positive or equivocal. IgM and, or IgG antibody to B. Burgdorferi are employed as an adjunct to patients with clinical symptoms suggestive of Lyme disease as it only tells us if the person has been infected with the spirochete (it does not determine if the person has an active infection). During the time that the ECM rash is present the serologic testing is often negative.
How to treat Lyme Disease?
- Early disease
- Doxycycline BID 10-21 days. Azithromycin or Erythromycin can be used if doxycycline is contraindicated, and, or the patient has a Penicillin allergy.
- Amoxicillin is the treatment of choice in children <8 years old, or in pregnancy x14-21 days.
- Late/severe disease
- IV ceftriaxone if 2nd/3rd AV heart block, syncope, dyspnea, chest pain, CNS disease other than CN7 palsy/Bell’s palsy (for example, meningitis)
- A single 200 mg dose of doxycycline given within 72 hours after an Ixodes Scapularis tick bite can prevent the development of Lyme disease in 87% of cases
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