Someone clutching their knee due to arthritic pain.

What is Lyme Arthritis?

Lyme arthritis, which is characterized by joint swelling and pain, is a condition that describes the most common advanced stage symptoms of Lyme disease, a bacterial infection spread by deer ticks to humans. Based on a study published in the Arthritis & Rheumatology journal, around 60% of people with unidentified, untreated Lyme disease develop Lyme arthritis.

However, Lyme arthritis is not the same as chronic Lyme disease. As its name suggests, chronic Lyme disease is a persistent medical condition that cannot be treated with only a single course of antibiotics. This condition is controversial in the medical landscape for two reasons. First, some patients get a positive chronic Lyme disease diagnosis despite lab tests not showing any proof of an infection. Secondly, some doctors claim that chronic Lyme disease symptoms go away when patients remain on antibiotics while others insist that it is a different disease altogether and long-term usage of antibiotics will only result in more side effects. Lyme arthritis, on the other hand, is a treatable symptom of Lyme disease that has advanced and resulted in arthritis complications.

How Common is Lyme Arthritis?

Lyme arthritis is estimated to affect approximately 33% of people with Lyme disease in the U.S., and between 3% and 15% of individuals with Lyme disease in Europe. Multitudes of studies have linked this condition with swelling and inflammation mainly of big synovial joints, with the most affected areas being the knee and ankle.

Children are the most susceptible to Lyme arthritis due to the high amount of time they spend outdoors in environments inhabited by ticks. Peak incidences are highest in children aged between 2 and 5 years, and in adults aged over 50 years. Although deer ticks are active between April and October, Lyme arthritis may begin at any time of the year because of the long and unpredictable time between the bite by an infected tick and the commencement of joint swelling.

What is the Cause of Lyme Arthritis?

The actual cause of Lyme arthritis is Lyme disease. This disease develops when deer ticks carrying borrelia burgdorferi bacteria bite and infect humans. After the bacteria have been introduced into the human body, they multiply quickly, spread around and attack other body parts like the joints. Once that occurs, the joints, especially bigger ones like the knee and ankle, swell and become painful. Later stages of Lyme arthritis symptoms usually appear after the early stages of Lyme disease symptoms, like rash and fever, have disappeared.

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What are the Primary Symptoms of Lyme Arthritis?

The primary Lyme arthritis symptoms are joint swelling and discomfort, which results in effusion and movement difficulties in the affected joint(s). Significant swelling usually occurs with little to no joint pain. The knee is the most commonly affected joint, but other joints in the body may be affected as well.

Lyme arthritis symptoms can be similar to those of other kinds of arthritis. For this reason, Lyme arthritis is difficult to diagnose, particularly if the patient never discovered a tick or tick bite or does not have any reason to think they may have Lyme disease. With that aside, below are some features that differentiate Lyme arthritis from other kinds of arthritis.

  • Unlike many forms of inflammatory arthritis, Lyme arthritis is not uniform on both sides. This means if one joint is affected, the other one will not necessarily be affected, too.
  • Lyme arthritis mostly triggers pain in just a few joints – typically fewer than five joints.
  • The pain caused by this late stage condition is not continuous. It is also not painful enough to stop someone from walking.
  • The pain could appear more painful than it actually feels. Patients can have an extremely swollen knee that is not all that painful.

How is Lyme Arthritis Treated?

This infectious bacterial disease is treated with antibiotics. Over 80% of people with this disease are healed after taking one or two courses of antibiotics. In approximately 10% to 20% of patients, when an additional course of antibiotics does not work, doctors usually opt for anti-rheumatic treatment.

Once the patient has completed the antibiotic treatment, it is advisable to wait at least six weeks to see if the treatment will work. If it does not work, another course of antibiotic treatment may be provided. If arthritis is still ongoing after the six weeks the second treatment with antibiotics has been completed, anti-rheumatic medications may be administered. Most doctors usually prescribe non-steroidal, anti-rheumatic medication and may inject corticosteroids into the arthritis-stricken joints, especially the knee joint.

Doctors may prescribe oral antibiotics for a month or intravenous ones for not less than two weeks. If patients are finding it difficult to comply with amoxicillin or doxycycline (strictly prescribed to patients aged more than 8 years of age), intravenous treatment with either cefotaxime or ceftriaxone may prove helpful. Treatment with antibiotics comes with a few mild side effects, such as nausea, vomiting and diarrhea.

Is Lyme Arthritis Preventable?

In parts of Europe and the U.S. where ticks are prevalent, it is hard to keep kids from getting bitten by tick(s), especially when they are outdoors, but for the causative organism to be transmitted to the host (the human body), the tick must remain attached to the host for up to 24 hours. So, children should be inspected each evening during the summer and any attached tick(s) removed right away to prevent transmission of the causative organism.

The use of antibiotics after a tick bite as a preventative measure is not recommended, but when the early signs of erythema migrans are detected, antibiotic treatment should be commenced. This treatment will kill the bacterium in its early stage and prevent development of Lyme arthritis.


Lyme arthritis should go away after proper treatment with antibiotics. If symptoms linger, look for a doctor who is willing to work with you to identify the actual cause of your joint pain. It is advisable to work with a doctor you trust and who can help you familiarize with your symptoms as well as teach you the best ways to manage them.