Development of a foundation for a case definition of post-treatment Lyme disease syndrome

The study objective is to demonstrate the clinical and research utility of an operationalized definition of post-treatment Lyme disease syndrome (PTLDS), as proposed by the Infectious Diseases Society of America.

Seventy-four patients with confirmed erythema migrans and 14 controls were enrolled. Patient-reported symptoms and health function (SF-36) were collected pre-treatment and at follow-up visits over 6 months post-treatment.

Eight (11%) patients met our operationalized definition of PTLDS, which included self-reported symptoms of fatigue, widespread musculoskeletal pain or cognitive complaints, and functional impact as measured by a T score of <45 on the composite SF-36. No controls met the functional impact criteria. Forty-three (60% patients returned to their previous health status when measured at 6 months post-treatment. Twenty (28%) patients had either residual symptoms or functional impact, but not both, and did not meet criteria for PTLDS.

This operationalized definition of PTLDS allows for identification of those patients who are treated for early Lyme disease and have significant post-treatment illness, as they have both residual symptoms and impact on daily life functioning. With further refinement and improvement of this operationalized definition, the true incidence of PTLDS can be determined and future studies can be designed to examine its pathophysiology and treatment.