Growing awareness of
Lyme disease, caused by the tickborne spirochete Borrelia burgdorferi has led to a marked increase in laboratory procedures to help in its diagnosis. Despite the frequent ordering of serologic tests specific for
Lyme disease, there remains confusion in the accurate interpretation of these tests. Because of the important cutaneous manifestations of B burgdorferi infection, dermatologists should understand the role of the laboratory in Borrelia-related conditions. This article reviews laboratory techniques available for the diagnosis of
Lyme disease. The role of histologic findings and culture, the sensitivity, specificity, and reproducibility of commonly used serologic tests, the effects of
disease duration and treatment on serologic results, and the future of laboratory diagnosis are described.