Document Type

Article

Publication Date

October 2007

Comments

This article has been peer reviewed. It is the authors' final version prior to publication in The Journal of Emergency Medicine 2007 (in press); the published version is available at http://dx.doi.org/10.1016/j.jemermed.2007.06.007. Copyright 2007 by Elsevier, Inc.

Abstract

To confidently diagnose and treat Lyme disease, the clinician must first understand the natural history of this disease, especially its protean early manifestations. Emergency physicians, primary care physicians, and other providers need to be vigilant in terms of the timely recognition of erythema migrans (EM), the unique marker of early localized stage 1 disease. The classic EM, originally described as a slowly expanding bull's eye lesion, is now recognized to be present in only the minority of cases (9%); the dominant morphologic lesion of EM is now recognized to be the diffusely homogenous red plaque or patch, which occurs in over 50% of cases. This update will define the current morphologic features of early Lyme disease, the indication for serologic studies, and the most recent treatment guidelines, including therapeutic pitfalls.