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Pain & other conditions
Lyme Arthritis
Also known as: Lyme disease arthritis
Joint inflammation caused by the tick-borne bacterium Borrelia burgdorferi, usually a swollen knee weeks to months after infection.
Video lesson
What it is
Lyme disease is common in the Northeast and Mid-Atlantic, including Pennsylvania. If early infection goes untreated, the bacteria can spread to joints. Lyme arthritis typically affects one or a few large joints.
Symptoms
A markedly swollen knee that is often less painful than it looks and comes and goes. Earlier signs may have included a bull’s-eye rash, fever, fatigue or facial palsy.
How it’s diagnosed
Two-tier Lyme antibody testing is almost always positive by the arthritis stage. Joint fluid can be tested by PCR, and other causes of a swollen joint are ruled out.
Treatment
A 28-day course of oral antibiotics such as doxycycline is first-line. If swelling persists, a second course or IV antibiotics may be used. Rarely, arthritis continues after the infection is cleared and is treated with anti-inflammatory medicines.
Living with it
Use tick repellent, check for ticks after outdoor time and remove them promptly. Early treatment of the rash prevents later complications.
At a glance
Category
Pain & other conditions
Also known as
Lyme disease arthritis
Reviewed by Farhan Tahir, MD, FACR
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