December 21, 2005
Paul G. Donohue, M.D.
DEAR DR. DONOHUE: My right knee and the fingers on my right hand suddenly swelled and became painful. My family doctor didn’t know what I had and sent me to an arthritis specialist. He asked if I had been sick in the past month. I had. I had diarrhea for about one week. After a series of tests, he said I had reactive arthritis. Reactive to what? Can you throw some light on this? — P.Z.
ANSWER: Reactive arthritis is joint swelling with severe joint pain that is a ”reaction” to a previous infection. The infection is often an intestinal infection usually producing diarrhea. Or it might be an infection of the urethra, the bladder’s emptying tube. It causes painful urination. Germs involved in this infection include the common diarrhea-producing germs — salmonella, Shigella and Campylobacter. The urethral infection is most often due to the chlamydia germ.
Anywhere from one week to a month after the initial infection, joint symptoms set in. The knee, ankle, foot, toes, wrist and fingers are the usual targets. The fingers take on the appearance of stuffed sausages.

The eyes can also become inflamed, and an eye doctor should be consulted if that happens.
A rash might break out on the palms and soles.
Anti-inflammatory drugs like Indocin can often control joint swelling and pain. If symptoms are resistant to those drugs, the sulfa drug sulfasalazine is beneficial. If the eye is a target, cortisone drops can quell the inflammation.
On the down side, joint symptoms can last for a considerable time in about a third of patients. Peculiarly and unexplainably, heel pain can be a consequence of this condition. A few patients have to put up with recurring joint swelling and pain.