Quick answer
Lyme arthritis is joint swelling caused by Lyme disease, most often in one knee. It usually starts one to a few months after an untreated infection, and the swelling can come and go or move between joints. It is treated with a 28-day course of antibiotics. A small group has swelling that lingers after treatment.
- About 1 in 4 Lyme disease cases reported to CDC involve arthritis. CDC notes reporting may overstate how often doctors see it.
- It typically starts within one to a few months after infection.
- The knee is most often affected. Other large joints, such as the shoulder, ankle, elbow, jaw, wrist and hip, can be involved.
- The first episode is treated with 28 days of oral antibiotics (doxycycline, amoxicillin or cefuroxime).
What Lyme arthritis feels like
The main sign is obvious swelling in one or a few joints. CDC describes:
- a swollen joint, most often a knee
- warmth, or pain when moving the joint
- swelling that comes and goes, or shifts from one joint to another
- in the shoulder, hip or jaw, swelling that can be hard to see
Earlier in the illness, CDC also lists aches that come and go in tendons, muscles, joints and bones. Those vague aches are different from the clear swelling of Lyme arthritis.
Not everyone with Lyme arthritis remembers a tick bite or a rash. A swollen knee may be the first sign. See all the symptoms of Lyme disease.
When it appears, and “years later”
CDC says Lyme arthritis typically starts one to a few months after infection, and MedlinePlus describes late-stage Lyme as appearing months or years after infection. That is why some people search for “Lyme disease arthritis years later.” There are a few possibilities:
- An untreated infection that has gone unnoticed can show up as arthritis later on. It is still treated with antibiotics.
- Antibiotic-refractory Lyme arthritis is swelling that persists or returns even after two courses of antibiotics (see below).
- Joint aches without swelling after treatment may be part of post-treatment Lyme disease syndrome. See our chronic Lyme disease page.
- Another cause. Many conditions cause joint pain, so new joint symptoms years after Lyme deserve a fresh evaluation.
CDC notes that untreated joint damage can be permanent, so a swollen joint is worth checking promptly. See the stages of Lyme disease for the bigger picture.
How it is diagnosed
CDC says antibody blood tests are very sensitive in Lyme arthritis. Testing fluid from the joint can add information but should not be the first test. Learn more in our Lyme test guide.
In children, CDC warns that Lyme arthritis can be mistaken for septic arthritis, a bacterial joint infection that may need surgery. Lyme arthritis generally does not. See Lyme disease in children.
Treatment
| Situation | What CDC and the guideline describe |
|---|---|
| First episode | 28 days of oral doxycycline, amoxicillin or cefuroxime. For children under 8, CDC lists amoxicillin or cefuroxime. |
| Improving but not gone | A second course of the same oral antibiotic, or watchful waiting |
| Little or no response | IV ceftriaxone for 14 to 28 days |
| Still swollen after two courses | More antibiotics have not been shown to help; referral to a rheumatologist |
The 2020 IDSA/AAN/ACR guideline adds that antibiotics beyond about 8 weeks in total are not expected to help after a course of IV treatment. MedlinePlus notes that pain relievers such as ibuprofen may be prescribed for joint stiffness. Your provider will tailor the plan to your age, health and allergies. See our treatment guide for more.
Antibiotic-refractory Lyme arthritis
In some people, swelling and pain continue or return even after two courses of antibiotics. CDC says the cause is not known but is thought to be driven by the immune system rather than live bacteria, and that more antibiotics have not been shown to improve it. A rheumatologist, a specialist in joint and immune conditions, can discuss other treatments aimed at the inflammation.
This can be frustrating, especially when a joint keeps swelling after you did everything right. It does not mean treatment failed you or that you are imagining it.
We are collecting real experiences about Lyme arthritis from people who have lived it, shared with their permission. As stories come in, they will appear here, clearly marked as personal experience rather than medical advice.
See a provider promptly for a swollen, warm joint, especially if you live in or have visited an area where Lyme is common. Get same-day care for a hot, very painful joint with fever, or if a child refuses to walk or bear weight, since other joint infections can look similar.
Frequently asked questions
What does Lyme disease joint pain feel like?
Lyme arthritis usually causes obvious swelling in one or a few large joints, most often a knee. The joint may feel warm or hurt when moved, and swelling can come and go.
Can Lyme arthritis appear years later?
Lyme arthritis usually starts within one to a few months of infection, but an untreated infection can show up as arthritis later. Swelling can also persist after treatment in some people. Any new swollen joint deserves an evaluation.
Which joints does Lyme arthritis affect?
The knee most often. CDC also lists the shoulder, ankle, elbow, jaw, wrist and hip.
How long is Lyme arthritis treated?
The first episode is treated with 28 days of oral antibiotics. If it does not respond, a second course, sometimes by IV, may follow.
Is Lyme arthritis permanent?
Most people improve with treatment. CDC notes untreated joint damage can be permanent, and a small group has swelling that persists after antibiotics and may need a rheumatologist.