Clinical judgment in Lyme disease

Among multisystemic disorders with inflammatory, 'rheumatic' manifestations, Lyme disease holds a special fascination. Its cause - Borrelia burgdorferi, a spirochetal bacterium transmitted to humans through tick bites - makes it, in effect, a human model of an infectious etiology for a connective tissue disorder. While live spirochetes appear to be present throughout the course of the disease, much of the tissue injury appears to be immunologically mediated. The disease may ultimately provide avenues by which to study many chronic inflammatory states. Although it did not come to medical attention in the United States until the mid-1970s, clinical subsets of what we now call Lyme disease have been recognized in Europe since early in this century. The disease is now known to occur worldwide, with cases reported on all continents except Antarctica. In the United States, it has been the most commonly reported tick-transmitted disease for the past several years and it seems both to be spreading geographically and to be increasingly recognized. Cases have been reported from 43 states. A typical case in the United States begins in the summer with a pathognomonic skin lesion, erythema chronicum migrans (ECM), and associated flu-like symptoms. If the patient does not receive treatment, these features are often followed weeks to months later by cardiac, neurologic, or joint disease. However, wide variation is seen in clinical presentation and course. A flu-like syndrome may be the only manifestation. Alternatively, a feature of late disease such as oligoarthritic inflammation may be the initial presentation when manifestations of early Lyme disease were absent, unrecognized, or misattributed. The two case presentations that follow illustrate the need for clinical judgment.