Purpose: To determine the long-term outcome of patients with culture-confirmed Lyme disease.
Methods: We analyzed data collected prospectively on adult patients from a highly endemic area in New York State who were diagnosed with early Lyme disease between 1991 and 1994. Patients with culture-confirmed erythema migrans were evaluated at baseline, 7 to 10 days, 21 to 28 days, 3 months, 6 months, 1 year, and annually thereafter. All patients were treated with antibiotics at the time of diagnosis.
Results: We evaluated 96 cases on 709 separate occasions (median, eight evaluations per case). The erythema migrans rash resolved within 3 weeks in all of the 94 evaluable cases, none of whom developed an objective extracutaneous manifestation of Lyme disease. Of the 81 cases who were followed for >/=1 year, all but 8 (10%) were asymptomatic at their last visit, a mean (+/- SD) of 5.6 +/- 2.6 years into follow-up, and only 3 (4%) were symptomatic at every follow-up visit. Intercurrent tick bites were reported by 45 cases (47%), and 14 (15%) developed a second episode of erythema migrans. Four other cases who were asymptomatic seroconverted between years 2 and 5.
Conclusion: The long-term outcome of patients with erythema migrans after antibiotic therapy was excellent, but patients from a highly endemic area in New York State remained at high risk of re-exposure to ticks and reinfection. Subjective symptoms during follow-up evaluations tended to be mild to moderate, intermittent, and associated with more symptomatic illness at the time of initial diagnosis.