Lyme Disease

Exam Cram

• Infection causes by Borrelia burgdorferi

• Presentation: recent tick bite/ hiking + rash (erythema migrans), fatigue, arthralgia and rarely meningitis

• Diagnosis: clinical, serology can be negative in first two weeks so treat prior to results

• Management: doxycycline

Outline

Assessment

History

• Tick bite or risk factors e.g. hiking

• Fatigue, arthralgia, rash

• Foreign travel

Examination

• Erythema migrans rash- circular erythema

• Eschar: black central area

Investigations

• CRP: raised

• Serology: can be negative within two weeks, but within late disease almost 100% sensitive

Diagnosis

Diagnostic criteria: clinical, using symptoms + serology

Differentials: chronic fatigue syndrome

Classification: location of body affected- systemic, septic arthritis, meningitis

Management

Start antibiotics prior to serology results (can be negative for first two weeks):

• Doxycycline 21 days

• Pregnancy: amoxicillin

Erythema Migrans

• Circular rash around tick bite

• High specificity to Lyme disease

Lyme Meningitis

• Similar history or rash, hiking, foreign travel, athralgia

• Presentation: headache, fever, cranial neuropathy

• CSF: raised lymphocytes, mildly raised protein and low glucose

• Management: tetracycline or ceftriaxone

References and Resources

Page written 2024.