It most commonly affects the knees, presenting with synovitis and joint effusions (collections of fluid within the joint capsules) lasting up to a year.
It has also been reported affecting the ankles, elbows, wrists and fingers.
It is usually painless, although pain in the absence of trauma can occur in a few cases.
There is usually no disability associated with the joint swelling, and recovery is usually complete.
[citation needed]The condition was described in 1886 by Henry Hugh Clutton in The Lancet.