Written by Babatunde Carew
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This review outlines current best practices for Lyme disease prevention, diagnosis, and treatment, and the limited evidence supporting prolonged treatment for “chronic Lyme disease.”
Tick talk
Lyme disease is the most common vector-borne infection in the temperate northern hemisphere, with hundreds of thousands of cases annually. Its growing significance stems from the expanding range of Ixodes ticks, early diagnostic limitations due to low serologic sensitivity, and controversy over persistent symptoms following standard antibiotic treatment.
Prevention
- Tick avoidance: Wear long sleeves/pants, use insect repellents (DEET, picaridin, permethrin-treated clothing).
- Tick checks: Daily checks and bathing within 2 hours of potential tick exposure may reduce transmission.
- Tick removal: Use fine-tipped tweezers to grasp the tick close to the skin and apply steady, gentle traction – leave mouthparts if they remain, they typically extrude on their own.
- Post-exposure prophylaxis:
- One RCT showed a single 200 mg dose of doxycycline within 72 hours reduced erythema migrans (EM) development by 87% (95% CI, 25%–98%).
- Prophylaxis recommended only for high-risk bites (Ixodes tick attached ≥36 hrs in endemic area) within 72 hours of tick removal.
Diagnosis
- Suspect Lyme in endemic areas when symptoms are consistent and tick exposure is possible, even without known tick bite, as Ixodes bites often go unnoticed.
- Early Localized Disease:
- Occurs 3 to 30 days (commonly 7 to 14 days) after an infected tick bite.
- Erythema migrans (EM) is diagnostic; serologic testing is not required.
- Often accompanied by systemic symptoms (fever, myalgia, lymphadenopathy).
- Early Disseminated:
- Usually occurs weeks to months after infection.
- May have multiple secondary EM lesions (smaller than primary, often mistaken for urticaria), neurologic signs, cardiac manifestations, arthritis.
- Serology not needed if EM present; otherwise, should perform serologic testing. Two-tier testing (ELISA + immunoblot or dual ELISA) preferred. IgM appears at 1-2 weeks; IgG at 2-4 weeks.
- Late Disseminated:
- Occurs months to years after initial infection.
- Common manifestations include intermittent or chronic mono-/oligoarticular arthritis, especially in knees, and neurologic changes.
- Diagnosis confirmed via serologic testing; PCR may assist in synovial fluid analysis. Fever and systemic symptoms are typically absent.
- Other Tick-Borne Illnesses: Consider co-infections (e.g., babesiosis, anaplasmosis).
Treatment
- Early Localized:
- Doxycycline 100 mg BID × 10 days.
- Neurologic/Cardiac Involvement:
- Mild: Oral doxycycline as above × 14-21 days.
- Severe (e.g., high-degree AV block, encephalitis): IV ceftriaxone 2 g/day × 14-21 days.
- Late Arthritis:
- Oral antibiotics for 28 days.
- If unresponsive, IV ceftriaxone for 2-4 weeks.
- Persistent Symptoms (Post-Treatment Lyme Disease Syndrome):
- Symptoms (fatigue, arthralgias, and “brain fog,” etc.) that persist > 6 months after treatment and are felt to be disabling. Affects ~10% of patients.
- No evidence that extended antibiotics are effective; focus on symptom management.
Source
Lyme Disease. Ann Intern Med. 2025 May;178(5):ITC65-ITC80. doi: 10.7326/ANNALS-25-01111. Epub 2025 May 13. PMID: 40354663
