In an adult with Lyme disease presenting with arthralgia, normal renal function, no tetracycline allergy, and not pregnant, is oral doxycycline sufficient?

Oral Doxycycline for Lyme Disease with Arthralgia

Yes, oral doxycycline 100 mg twice daily for 28 days is the appropriate and sufficient treatment for Lyme arthritis in an adult with normal renal function, no tetracycline allergy, and who is not pregnant. 1, 2

Treatment Regimen

• Administer doxycycline 100 mg orally twice daily for 28 days (often rounded to 30 days in practice) as the first-line therapy for Lyme arthritis without neurologic involvement 1, 2
• This 28-day duration is specifically validated for Lyme arthritis and differs from the shorter 10-14 day courses used for early localized disease 2
• Clinical trial data demonstrates resolution of arthritis in 18 of 20 patients treated with this regimen 2

Critical Pre-Treatment Assessment

Before initiating oral therapy, you must carefully screen for neurologic involvement, as this would change management to parenteral antibiotics:

• Assess for subtle neurologic symptoms including distal paresthesias, memory impairment, radiculopathy, or meningeal signs 1, 3
• If any neurologic symptoms are present, parenteral ceftriaxone 2 g daily for 14-28 days is required instead of oral therapy 1, 3
• Isolated arthralgia without objective arthritis or neurologic findings can be treated with the standard oral regimen 1

Administration Guidelines

• Take with 8 ounces of fluid to reduce esophageal irritation 2
• May be taken with food to minimize gastrointestinal intolerance 2
• Counsel patients to avoid sun exposure due to photosensitivity risk 2

Management of Persistent Arthritis

If arthritis persists after the initial 28-30 day course:

• Consider a second 4-week course of oral antibiotics before escalating to IV therapy 2
• Reserve IV ceftriaxone for patients who fail two courses of oral therapy or have PCR-confirmed persistent infection 2
• Some patients develop antibiotic-refractory arthritis that requires symptomatic therapy rather than additional antibiotics 1

Monitoring for Co-infections

Consider co-infection with Babesia microti or Anaplasma phagocytophilum if:

• High-grade fever persists >48 hours despite appropriate Lyme treatment 3
• Unexplained leukopenia, thrombocytopenia, or anemia develops 3
• Initial symptoms are more severe than typically seen with Lyme disease alone 3
• Doxycycline provides coverage for HGA but not babesiosis 3

Common Pitfalls to Avoid

• Do not use first-generation cephalosporins (e.g., cephalexin) as they are ineffective against B. burgdorferi 1, 4
• Do not use fluoroquinolones, metronidazole, or macrolides for Lyme arthritis as they lack efficacy 1
• Do not prescribe doxycycline if the patient is pregnant, lactating, or <8 years old 2
• Do not extend therapy beyond 28-30 days for the initial course without evidence of treatment failure 2