Clinical Definition

Lyme disease is a vector-driven infectious disease caused by the Borrelia burgdorferi bacterium from the bite of a tick. The majority of cases present with acute signs and symptoms as the body mounts an immune response, including the hallmarkerythema migrans rash (it looks like a target) which occurs within one month of the bite. Bacteria spread throughout the body via the lymphatic system, which gives rise to varied, systemic symptoms.

In Our Own Words

A bull’s eye rash is the hallmark sign of Lyme disease, which is caused by bacteria from a tick bite. While the majority of patients (as many as 80 percent) exhibit this classic rash, some do not. Many experience flu-like symptoms, fatigue or painful, swollen joints, but some do not. The disease (first traced and publicized in Lyme, Conn.), can cause nerve, heart and joint problems, especially if it goes untreated. Symptoms from Lyme disease may continue for months or even years in some cases. Awareness and early treatment are crucial.