What is the recommended diagnostic workup and treatment for suspected Lyme disease?

From the Guidelines

The recommended diagnostic workup for suspected Lyme disease begins with a two-tier testing approach: an initial enzyme immunoassay (EIA) or immunofluorescence assay (IFA), followed by a Western blot if the first test is positive or equivocal, as recommended by the study published in Emerging Infectious Diseases 1.

Diagnostic Approach

The two-tier testing approach is crucial because Lyme serology can be falsely negative in early disease (less than 30 days from tick bite) 1. Clinical judgment remains important when the pretest probability is high, such as in patients with erythema migrans in endemic areas.

• The sensitivity of the two-tiered testing is low (30%–40%) during early infection, but it increases to 70%–100% for disseminated Lyme disease 1.
• Specificity is high (>95%) during all stages of disease 1.

Treatment Approach

Treatment depends on the disease stage and manifestations.

• For early localized Lyme disease (erythema migrans rash), doxycycline 100 mg twice daily for 10-14 days is the first-line treatment for adults, as per the guidelines outlined in Clinical Infectious Diseases 1.
• Alternatives include amoxicillin 500 mg three times daily or cefuroxime axetil 500 mg twice daily for 14-21 days.
• Children under 8 years should receive amoxicillin 50 mg/kg/day divided into three doses (maximum 500 mg per dose) for 14-21 days.
• For early disseminated or late Lyme disease, treatment duration extends to 14-28 days.
• Neurologic manifestations like facial palsy typically require doxycycline, while more severe neurologic involvement may need intravenous ceftriaxone 2 g daily for 14-28 days.
• Lyme carditis and arthritis also have specific treatment protocols, with persistent arthritis sometimes requiring longer courses.

Importance of Prompt Treatment

Prompt treatment is essential as it prevents progression to later stages of disease. The guidelines emphasize the importance of clinical judgment and the two-tier testing approach for accurate diagnosis and effective treatment of Lyme disease 1.

From the FDA Drug Label

The Jarisch-Herxheimer reaction is a systemic reaction, that may occur after the initiation of penicillin therapy in patients with syphilis or other spirochetal infections (i.e., Lyme disease and Relapsing fever).

The recommended diagnostic workup and treatment for suspected Lyme disease is not directly addressed in the provided drug label.

• The label discusses the Jarisch-Herxheimer reaction, a systemic reaction that may occur after initiation of penicillin therapy in patients with spirochetal infections, including Lyme disease.
• However, it does not provide information on the diagnostic workup or treatment for Lyme disease itself.
• Serological testing for Lyme disease is not mentioned in the label 2.

From the Research

Diagnostic Workup for Suspected Lyme Disease

• The approach to diagnosing Lyme disease varies depending on the probability of disease (based on endemicity and clinical findings) and the stage at which the disease may be 3.
• In patients from endemic areas, Lyme disease may be diagnosed on clinical grounds alone in the presence of erythema migrans, and these patients do not require serologic testing 3.
• When the pretest probability is moderate, serologic testing should be performed with the complete two-step approach in which a positive or equivocal serology is followed by a more specific Western blot test 3.
• Samples drawn from patients within four weeks of disease onset are tested by Western blot technique for both immunoglobulin M and immunoglobulin G antibodies; samples drawn more than four weeks after disease onset are tested for immunoglobulin G only 3.

Treatment for Lyme Disease

• Every manifestation of Lyme borreliosis needs to be treated with antibiotics, and the type of antibiotic applied and duration of treatment will depend on the stage and severity of the disease 4.
• Erythema migrans, Borrelia lymphocytoma, Lyme arthritis, and acrodermatitis chronica atrophicans are primarily treated orally with doxycycline, amoxicillin, cefuroxime, or azithromycin 4.
• If neurological symptoms, severe Lyme carditis, or eye manifestations are present, intravenous treatment is initially recommended with ceftriaxone, cefotaxime, or penicillin G 4.
• The recommended treatment of Lyme disease is evolving, and important questions remain unanswered, such as the effectiveness of inexpensive oral regimens versus more costly intravenous antibiotics 5.
• Both oral doxycycline and parenterally administered ceftriaxone were equally effective in preventing the late manifestations of disease in patients with acute disseminated Lyme disease but without meningitis 6.

Serological Testing for Lyme Disease

• The use of serologic testing and its value in the diagnosis of Lyme disease remain confusing and controversial for physicians, especially concerning persons who are at low risk for the disease 3.
• Serologic testing should be performed with the complete two-step approach in which a positive or equivocal serology is followed by a more specific Western blot test 3.
• Patients who show no objective signs of Lyme disease have a low probability of the disease, and serologic testing in this group should be kept to a minimum because of the high risk of false-positive results 3.
• When unexplained non-specific systemic symptoms such as myalgia, fatigue, and paresthesias have persisted for a long time in a person from an endemic area, serologic testing should be performed with the complete two-step approach 3.