Lyme disease, also known as Lyme borreliosis, is an infectious disease caused by the Borrelia bacterium which is spread by ticks. The most common sign of infection is an expanding area of redness on the skin, known as erythema migrans, that appears at the site of the tick bite about a week after it occurred. The rash is typically neither itchy nor painful. Approximately 70–80% of infected people develop a rash. Other early symptoms may include fever, headache and tiredness. If untr Lyme disease...