De Quervain's tenosynovitis: De Quervain's tenosynovitis is inflammation of tendons on the side of the wrist at the base of the thumb. These tendons include the extensor pollicis brevis and the abductor pollicis longus tendons. De Quervain's tenosynovitis typically is associated with pain when the thumb is folded across the palm and the fingers are flexed over the thumb as the hand is pulled away from the involved wrist area. (This is referred to as the Finklestein sign.)

Treatment of De Quervain's tenosynovitis includes any combination of rest, splinting, ice, anti-inflammation medication, and/or cortisone injection. Surgery is only rarely necessary.