Lyme disease is an infection caused by bacterium carried by deer ticks. If caught early, it is easily treated with antibiotics. If left untreated, the infection can spread to the joints, heart, and nervous system, causing a complex debilitating disorder that is more difficult to treat.
The bacterium that causes Lyme disease is called Borrelia burgdorferi. People get infected through a bite of an infected black-legged tick, which feed from mammals, birds, reptiles and amphibians. Humans may get bit by a tick when walking through high grasses and shrubs. Lyme disease does not spread from person to person.
Early symptoms resemble a mild flu and include fever, headache, fatigue, chills and swollen lymph nodes. A characteristic red skin rash in the shape of a bull’s eye develops in most, but not all people, at the place of the bite three to 30 days later.
If these first signs are missed or ignored by the infected person and antibiotic treatment is not initiated, more serious symptoms may develop. Over the course of several weeks, there may be heart and nervous system issues, Bell’s palsy (loss of muscle tone on one or both sides of the face), severe headache, neck stiffness due to inflammation of the spinal cord (meningitis), pain and swelling in the large joints, shooting pains causing sleep problems and heart palpitations.
If left untreated, over half of the people will develop sporadic bouts of arthritis, particularly in the knees. In some, neurological issues -- such as shooting pains, numbness or tingling in the hands and feet -- and short-term memory problems will worsen months to years after the infection.
Lyme disease is diagnosed based on the presence of flu-like symptoms, rash, and possibility of exposure to infected ticks. Laboratory tests that find antibodies against B. burgdorferi in the blood of the infected person can help to confirm the diagnosis. However, these may be undetectable early in the infection.
When found early, Lyme disease can be treated successfully with antibiotics. The ones commonly used for are taken by mouth and include doxycycline, amoxicillin or cefuroxime axetil. People with nerve or heart involvement may need intravenous therapy with ceftriaxone or penicillin. There are no proven treatments for complications caused by untreated Lyme disease. These should be addressed on an individual basis based on the person's medical history and overall health.
Most people who are treated with antibiotics early respond completely to the treatment. However, some people continue to show symptoms. Since there is no proof of continued infection, the exact cause of this phenomenon is unknown. When it comes to Lyme disease, prevention is key. Apply tick repellants containing DEET before spending time outdoors.