The lesions in this patient developed 2 weeks after hiking in the woods of the Upper Midwest in April. If left untreated, this patient is at risk for development of all of the following except:
a. Fever, lymphadenopathy, meningismus
b. Carditis
c. Ischemic bowel
d. Cranial nerve palsies
e. Arthritis
Lyme Disease
Answer: c
• Causative agent, Borrelia burgdorferi, is transmitted by Ixodes ticks
• Highest incidence is during spring and summer
• Tick must be attached more than 24 hours for transmission to occur
• Stage 1: Within 30 days of infection, erythema chronicum migrans occurs in 80% of patients and may be associated with fever, lymphadenopathy, and meningismus. The rash resolves within 4 weeks
• Stage 2: Onset is weeks to months after stage 1. Neurologic abnormalities occur in 10% to 15% of patients. Carditis occurs in 10% of patients
• Stage 3: Begins months to years after infection. Arthritis occurs in 50% of untreated patients, becoming chronic in 10% to 20%
• Enzyme-linked immunosorbent assay is positive for diagnosis within 2 to 6 weeks
• Early-stage disease may be treated with doxycycline, amoxicillin, or cefuroxime
• Neurologic or cardiac involvement requires high-dose ceftriaxone or penicillin G