Immediate Treatment for Suspected Lyme Disease

Diagnosis and Treatment

The American College of Physicians recommends starting doxycycline immediately for suspected Lyme disease without waiting for serologic testing, and discontinuing antibiotics if both IgG and IgM are negative and clinical suspicion is low 1
The Infectious Diseases Society of America suggests that doxycycline 100 mg twice daily should be started immediately if erythema migrans is present, as this is a clinical diagnosis that does not require laboratory confirmation 2, 3, 4
The Centers for Disease Control and Prevention recommend beginning treatment for typical erythema migrans even with negative serology 2
Doxycycline has the critical advantage of treating co-infection with Human Granulocytic Anaplasmosis (HGA), which may occur simultaneously with Lyme disease 5, 1

The American College of Physicians states that serologic testing is often negative in early Lyme disease and should not be used to exclude the diagnosis when erythema migrans is present 6
The Infectious Diseases Society of America recommends stopping antibiotics if both IgG and IgM are negative, and no erythema migrans rash is present, and no objective signs of disseminated disease are found, and an alternative diagnosis is identified 6, 2, 3

The Infectious Diseases Society of America suggests that doxycycline 100 mg twice daily for 10-14 days is recommended for early localized or early disseminated Lyme disease with erythema migrans 3, 4, 1
The Centers for Disease Control and Prevention recommend extending treatment to a minimum of 10 days if concurrent anaplasmosis is suspected 2, 1

The American College of Physicians warns that first-generation cephalosporins (e.g., cephalexin) should never be used as they are completely ineffective against B. burgdorferi 5, 4, 1
The Infectious Diseases Society of America advises against ordering serologic testing to "rule out" Lyme disease in patients without clinical findings suggestive of Lyme disease 6
The Centers for Disease Control and Prevention recommend avoiding macrolides (azithromycin, clarithromycin, erythromycin) as first-line therapy as they are significantly less effective than doxycycline or amoxicillin 3, 5, 4

The American College of Physicians recommends amoxicillin 500 mg three times daily for 14 days (adults) if doxycycline is contraindicated 2, 3, 4
The Infectious Diseases Society of America suggests cefuroxime axetil 500 mg twice daily for 14 days (adults) if doxycycline is contraindicated 2, 3, 4

The Centers for Disease Control and Prevention recommend reassessing if objective signs persist or worsen after completing appropriate antibiotic therapy, including persistent or worsening erythema migrans after 14 days of treatment, and development of new objective manifestations (arthritis, neurologic findings, carditis) 2, 3, 6