Impact of patient age on clinical features, serologic test reactivity and long-term outcome of culture-confirmed early Lyme disease.

Whether age at time of diagnosis impacts the clinical presentation or long-term outcome of early Lyme disease is unknown. Subjects enrolled in this study had culture-confirmed early Lyme disease and were followed up annually in a long-term prospective study. Subjects ≤50years of age were compared with those who were ≥51years of age at time of study entry. Of the 283 enrolled subjects, the ≥51year old age group was significantly more likely to be female (P=0.0095) and to be compliant with long-term follow-up of at least 11years duration (P=0.0119). There were no significant differences between the two age groups with regard to any of the other variables assessed at presentation. For the 128 subjects who were followed up for 11-20years, there was no significant difference between the two age groups in the frequency, number or type of residual symptoms. The older age group at study entry, however, was significantly more likely to develop an intercurrent comorbidity (P=0.0017), and there was a trend toward a greater likelihood of having an intercurrent hospitalization (P=0.0311). Among the 128 subjects followed up for 11-20years, the older age group at study entry returned for a significantly greater number of follow-up visits (P=0.0129). In conclusion, older age at the time of diagnosis of early Lyme disease did not impact the initial clinical features or long-term outcome of this infection. Not unexpectedly, older patients had more comorbidities during long-term follow-up.