Arthritis Q&A by Dr. Shiel

Answer:

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Yersinia is a bacterium that can cause infection in the colon (infectious colitis). This can lead to a form of severe gastroenteritis called dysentery. It seems that some people's immune systems can "react" to this form of dysentery and become misdirected. This misguided immune system actually then attacks tissues of the body. This attack typically features inflammation of joints (arthritis). This form of arthritis is referred to as Reactive Arthritis. For more, please see MedicineNet.com's Reactive Arthritis article.

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