Lyme Arthritis, Borreliosis
What is Lyme disease?
Lyme disease is a bacterial infection spread by a bite from an infected tick, and characterized by skin changes, flu-like symptoms, and joint inflammation. Since many of the signs and symptoms are nonspecific (could be indicative of a variety of disorders), the disease is difficult to diagnose. The disease may have three stages, and symptoms of advanced disease may take months or even years to develop. Untreated disease may affect the brain, heart and joints. The majority of individuals develop chronic arthritis (joint inflammation). Ticks infected with Lyme disease usually live on deer but can infest dogs. Most cases have occurred in the northeastern US, but the disease has also been reported along both US coasts, in the upper Midwest, and in other countries.
How is it diagnosed?
History: Individuals may report history of a tick bite or exposure to a particular type of tick, However, only 30% of individuals infected with Lyme disease recall a tick bite.
Symptoms will vary with the stage of disease and the time since exposure. Early symptoms may arise within two to thirty days. Symptoms of heart, brain, or joint disease may appear several weeks or months after exposure. Chronic disease may develop at any time within two years of the initial infection.
A red dot may appear at the site of the tick bite, gradually expanding into a reddened area several inches across. In about half of the cases, additional smaller round red areas form. Flu-like symptoms such as fever, chills, extreme fatigue, headaches, intermittent muscle and joint pain, and a mild neck stiffness usually develop next. If not treated, the signs and symptoms of the first stage disappear after a few weeks, making a diagnosis difficult.
After a few weeks, or even months, the second stage develops. This stage may involve the musculoskeletal system (pertaining to both bones and muscles), nervous system, and/or heart. Joint pain occurs in more than 60% of the cases, and is the most common symptom of this stage. Intermittent or temporary joint pains are often followed by more intense pain and swelling of the knees or other large joints. Lasting weeks to months, these episodes of joint inflammation may be followed by periods of remission (a period of time during which symptoms lessen or disappear). If left untreated, however, these joint symptoms can lead to persistent symptoms and disability. Neurologic symptoms of this stage may include constant headache, stiff neck, facial nerve palsy (facial droop) involving one or both sides of the face, and pain or weakness in extremities and trunk. Cardiac symptoms are usually dizziness or fainting (syncope) from various degrees of heart block (disturbances in contractions).
Months to years after the tick bite, the third stage may occur. This stage is dominated by disorders of the musculoskeletal and the nervous system. Joint pain involves the large joints, is more persistent, and frequently lasts more that a year without remission. Impaired memory, difficulty concentrating, and sleep disorders are common complaints. Pain in the spine is often accompanied by tingling or shooting pains in the extremities.
Physical exam in an early infection may reveal a small, red, flat or slightly raised lesion surrounded by a round, bull's-eye-like red rash with a pale center. The rash will increase in size, then fade, and may reappear at another site. The area doesn't itch but may feel warm to the touch. Smaller additional red, round rashes may appear at other body sites.
Symptoms of heart, joint or brain disease will become apparent within several weeks or months. Heart abnormalities observed during physical exam might include irregular heartbeat (arrhythmias) due to heart block. Joint inflammation is usually asymmetric (does not correspond in size or amount to same joint on opposite side of the body), and the knee joint is most frequently involved. Neurological symptoms may include impaired memory, difficulty concentrating, diminished sensation to touch, stiff neck or back, and facial droop on either one or both sides (unilateral or bilateral).
Tests: The diagnosis of Lyme disease can be confirmed by testing the blood for antibodies to the bacterial agent (spirochete) causing the disease. The test may give variable results that depend upon the stage of the disease and the individual's immune response. Infected individuals may not show antibodies during the first stage of the disease. In later stages, most have antibodies, but a small percentage still do not.
Routine laboratory tests are helpful in excluding other diseases that can mimic Lyme disease. The electrocardiogram (ECG) can show variable degrees of heart block. X-rays of the bone can reveal erosive changes due to chronic inflammation.
How is Lyme disease treated?
Lyme disease responds well to treatment, especially if given in the early stages of infection. In some cases, the infection subsides spontaneously. Relapse can occur in any stage of the illness, even after antibiotic treatment.
Antibiotics are prescribed for as long as twenty days to treat the infection during early stages, or for a month or longer when treating chronic inflammation.
Over-the-counter pain relievers may be used to reduce fever and inflammation. If the disease is more advanced, severe joint pain and inflammation may require treatment with non-steroidal anti-inflammatory or corticosteroid drugs.
A temporary cardiac pacemaker may be needed for severe heart block. Since the heart block is transient (temporary), a permanent pacemaker is rarely required. Chronic joint inflammation that is resistant (refractory) to treatment may eventually require arthroscopic synovectomy (removal of the membrane lining the joint).
What might complicate it?
The recurrence of infectious arthritis, even with antibiotic therapy, or the development of chronic arthritis in untreated infections may complicate the disease. Chronic arthritis may lead to stiffening of the joints and movement limitations. Individuals who went without antibiotic treatment for a longer period of time have more chronic joint symptoms and memory impairment. Cardiac complications might include arrhythmias or severe heart block. Serious neurologic disorders (such as meningitis or encephalitis, and demyelinating disorders similar to multiple sclerosis) have been associated with Lyme disease, and can lead to permanent impairment or death.
The prognosis is very good if the infection is treated promptly with antibiotics. With appropriate antibiotic therapy, the rash should begin to fade within a week. Later stages of the disease can take weeks to months to respond to therapy and can recur despite therapy. Individuals with later stage disease may require long-term follow-up. The outcome of untreated disease is difficult to predict. Sometimes, the infection subsides with no lasting effects. More often, untreated infections progress to chronic arthritis, which may result in partial or permanent disability. The prognosis for neurologic or cardiac complications varies with the severity of infection and response to treatment.
Other bacterial infections may invade a joint and cause infectious arthritis similar to that found in early Lyme disease. Other viral, bacterial and fungal causes of meningitis or encephalitis may give symptoms similar to neurological complications of Lyme disease.
Infectious disease specialist, orthopedic surgeon, neurologist and cardiologist.
Last updated 17 December 2011