Abstract
Antibiotic efficacy was studied in 113 patients with erythema chronicum migrans, the 1st manifestation of Lyme disease. Erythema chronicum migrans and its associated symptoms resolved faster in patients given penicillin or tetracycline (median duration, 4 and 2 days, respectively) than in untreated patients (10 days; P < 0.001 and P = 0.005, respectively), Erythromycin had no significant effect. Although the frequency of subsequent neurologic and cardiac abnormalities was similar in all 4 groups, significantly fewer patients given penicillin developed arthritis than did untreated patients (P = 0.001). Among 15 patients with arthritis who were followed for at least 29 mo., the total duration of joint involvement was shorter in penicillin-treated patients (median, 4 wk) than in untreated patients (17 wks; P = 0.019). Although the clinical manifestations of the disease may fluctuate yearly in frequency and influence apparent antibiotic effect, penicillin therapy apparently shortens the duration of erythema chronicum migrans and may prevent or attenuate subsequent arthritis.