(HealthDay News) -- Lyme disease, caused by the bacterium B. burgdorferi, is transmitted by biting deer ticks that are quite small and may be difficult to see.
Within 30 days of a deer tick bite, a circular red patch of about five inches' diameter often appears. The rash, if it shows up at all, commonly resembles a bull's eye, the U.S. Food and Drug Administration says.
Other symptoms may include:
Lyme is treatable, especially in its early stages, with antibiotics. But left untreated, the disease could progress to arthritis and problems of the heart and nervous system. If you have these symptoms, see your doctor without delay.