Erythema chronicum migrans (EM)This image depicts the posterior right shoulder region of a patient who'd presented with the erythema migrans (EM) rash
characteristic of what was diagnosed as Lyme disease, caused by the bacterium, Borrelia burgdorferi. Note the characteristic
red, expanding rash called erythema migrans (EM).
B. burgdorferi bacteria are transmitted to humans through the bite of infected ticks. Typical symptoms include fever, headache,
fatigue, and a characteristic skin rash called erythema migrans. If left untreated, infection can spread to joints, the heart,
and the nervous system. Lyme disease is diagnosed based on symptoms, physical findings, e.g., rash, and the possibility of
exposure to infected ticks and laboratory testing.
Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics.
Steps to prevent Lyme disease include using insect repellent, removing ticks promptly, applying pesticides, and reducing tick habitat.
The ticks that transmit Lyme disease can occasionally transmit other tickborne diseases as well.