Rheumatoid arthritis and Lyme disease are two conditions that can affect a person’s joints and nervous system. It is possible to have both conditions at once.
If a person thinks that they have either condition, they should seek medical attention. A doctor can diagnose the cause of the symptoms and work with the individual to make a treatment plan.
In this article, learn more about the similarities and differences between Lyme disease and rheumatoid arthritis.
Lyme disease and rheumatoid arthritis share some of the same symptoms, including:
A person with Lyme disease often experiences these symptoms in the early stages of the condition. Some people may also develop a rash.
The symptoms of Lyme disease may go away and reappear months to years later. Doctors call this condition late-stage Lyme disease.
The later stages of the disease can also affect the joints, which can cause Lyme arthritis. People may confuse Lyme arthritis symptoms with those of rheumatoid arthritis.
Although rheumatoid arthritis tends to involve the hands and feet while Lyme arthritis often affects the knees, people with rheumatoid arthritis may also experience symptoms in the knees.
If a person does experience Lyme arthritis, a doctor will prescribe or recommend medications similar to those that they use to treat Lyme disease. In some cases, this will follow treatment with antibiotics.
Common examples include disease-modifying antirheumatic drugs (DMARDs) and nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen.
Lyme disease typically resolves with treatment, although this can sometimes take many years. Conversely, rheumatoid arthritis is usually a chronic condition. Other differences include:
Lyme disease and rheumatoid arthritis have different causes. Lyme disease is the result of a bite from a tick that has become infected with a type of spirochete bacteria called Borrelia burgdorferi.
Doctors still do not know exactly what causes rheumatoid arthritis. However, the combination of genetics, environmental factors (especially smoking), and a history of certain infections seems to play a role in triggering the disease.
Rheumatoid arthritis most commonly affects the finger and toe joints at first, causing pain and discomfort.
In comparison, Lyme disease tends to affect one knee joint, resulting in swelling and discomfort.
According to 2015 research, Lyme disease rarely causes symmetrical arthritis. However, in rheumatoid arthritis, the condition usually affects a person’s joints equally on both sides of the body.
In Lyme arthritis, a person may have just one affected joint on one side of the body, although some people experience symptoms in several joints.
Lyme arthritis also does not typically cause severe pain when a person moves their joints, unlike rheumatoid arthritis.
The treatment options for Lyme disease depend on when a person receives the diagnosis. If a doctor can diagnose Lyme disease in its earliest stages, they can prescribe antibiotics to treat the infection, which can often prevent the development of late-stage arthritis.
Examples of antibiotics that doctors use to treat Lyme disease include amoxicillin, cefuroxime, and doxycycline.
Most people respond well to these treatments, and their body clears the bacteria from its system.
If a person later develops arthritis, a doctor may treat the symptoms with a longer course of antibiotics.
The best treatment for rheumatoid arthritis will depend on the severity of a person’s symptoms.
Some people can take NSAIDs in the earlier stages to reduce pain and swelling. Those with more severe symptoms may need to take DMARDs, such as methotrexate.
Doctors may also prescribe medications called biologics that alter the body’s response to inflammation.
Lyme arthritis will usually respond to treatment, and it often resolves within about a year. Some people will experience recurrent bouts of Lyme arthritis, but this is less likely after treatment.
Rheumatoid arthritis is a chronic inflammatory condition that causes a person to have periods of relapse and remission. The condition currently has no cure. However, effective treatments can prevent disease progression and minimize damage to the body.
Many people will experience progressive symptoms that get worse over time, especially if treatment is ineffective or a person does not have access to treatment.
While a tick bite causes Lyme disease and can lead to arthritis, some people are not aware that they ever received a tick bite, which makes it more difficult for a doctor to consider this diagnosis.
The doctor will begin by asking a person about their medical history and their current symptoms, including when the person first noticed them, what makes them worse, and what makes them better.
They may use the following tests to aid diagnosis:
- For Lyme disease: A saliva or blood test to check for antibodies to the B. burgdorferi bacteria and tests on a person’s synovial (joint) fluid for the presence of DNA belonging to the tick bacteria.
- For rheumatoid arthritis: Blood tests to determine the erythrocyte sedimentation rate (ESR) and look for rheumatoid factor, anti-citrullinated protein antibodies, and C-reactive protein. The doctor will also need to rule out infection with the Hepatitis C virus.
An estimated 45–75% of people with rheumatoid arthritis will test positive for rheumatoid factor. A higher percentage will test positive for anti-citrullinated protein antibodies.
In addition to these tests, the doctor may order imaging or ultrasound scans to identify early signs of damage to the joints.
Doctors may have to conduct a variety of tests and ask a person to try different treatments before making a conclusive diagnosis.
It is possible that a person could already have rheumatoid arthritis and then contract Lyme disease after a tick bite.
Lyme disease and rheumatoid arthritis are two conditions that share some similar symptoms, but many key differences exist between them.
A doctor can use medical tests to determine whether a person has either or both conditions.