Lymedisease is a tick-borne illness caused by the spirochete B burgdorferi. Lymedisease can be divided into early disease (stage 1, EM), disseminated infection (stage 2), and late disease (stage 3, persistent infection). The first stage involves the skin, followed by stages 2 and 3, which often affect the skin, joints, CNS, and heart. However, any of the stages may fail to appear or may overlap with one another
|Localized erythema chronicum migrans||Early infection|
|Disseminated infection||Within days or years|
|Persistent infection||Months to years|
Lyme disease is a bacterial disease caused by Borrelia burgdorferi. The bacterium is transmitted to humans via a tick bite. Within 1 to 2 weeks after being infected, a “bull’s-eye” rash can develop at the tick bite site accompanied by fever, headache, and muscle or joint pain. Some people may have Lymedisease and not have any early symptoms. However, others can have a fever and other “flu-like” symptoms without a rash.
The primary vector of Lyme disease in the U.S. is the black-legged deer tick (Ixodes scapularis) . Other Ixodes ticks are also known to transmit the disease. Lyme disease is maintained in wild rodent populations, on which the larval and nymphal ticks develop. These immature ticks pick up the disease organism when they suck the blood of infected rodents. The nymphal and adult ticks then seek a larger host, such as deer or humans, to obtain their final blood meal and transmit the disease when they feed.
Lyme disease may be hard to diagnose because its symptoms are like those of many other illnesses. Your doctor will take a careful medical history and do a physical examination to help diagnose early Lyme disease. You may be asked whether you have recently visited an area where you may have been exposed to ticks. The doctor will ask about your symptoms and look for physical signs that may indicate Lyme disease. The clearest physical sign is an expanding, circular red rash (called erythema migrans). See a picture of a Lyme disease rash.
The often vague, flu-like symptoms of Lyme disease can easily be misdiagnosed as another illness(such as chronic fatigue syndrome).