In 1895, a Swiss surgeon, Fritz de Quervain, published five case reports of patients with a tender, thickened first dorsal compartment at the wrist. [1, 2, 3, 4] The condition has subsequently borne his name, de Quervain tenosynovitis. De Quervain tenosynovitis is an entrapment tendinitis of the tendons contained within the first dorsal compartment at the wrist; it causes pain during thumb motion.
Surgeons have had more than 100 years of experience with de Quervain tenosynovitis. The described treatment options are widely accepted, and no significant controversies exist. No significant changes in diagnosis and treatment are anticipated for this lowly, yet irksome, condition. 
For patient education resources, see Tendinitis.
The tendons of the abductor pollicis longus and the extensor pollicis brevis pass through the first dorsal compartment. The abductor pollicis longus tendon is usually multistranded. The extensor pollicis brevis tendon is typically much smaller than even a single slip of the abductor pollicis longus tendon, and it may be congenitally absent. A septum separating the first dorsal compartment into distinct subcompartments for the abductor pollicis longus tendons and the extensor pollicis brevis tendon is often noted at surgery. 
The tendons of the abductor pollicis longus and the extensor pollicis brevis are tightly secured against the radial styloid by the overlying extensor retinaculum. Any thickening of the tendons from acute or repetitive trauma restrains gliding of the tendons through the sheath. Efforts at thumb motion, especially when combined with radial or ulnar deviation of the wrist, cause pain and perpetuate the inflammation and swelling.
The most common entrapment tendinitis of the hand and wrist is trigger digit,  followed by de Quervain tenosynovitis, though the latter occurs only about one twentieth as often as does trigger digit.
Relief is permanent following successful surgery. Some patients who have been successfully treated with injections may have recurrent symptoms when they return to lifting infants aged 6-12 months. This author would suggest the following: Relief is usually permanent.