De Quervain's tenosynivitis is tendonitis to the thumb and a swelling of the tendon sheath passing along the distal radial aspect of the wrist. This sheath runs through a tight tunnel holding the tendon down to bone and this swollen sheath passing through a tight tunnel results in significant pain.

For De Quervain's disease there are three modes of treatment:

• no treatment
• conservative treatment (ice, rest, steroid injections, physical therapy)
• surgery

Conservative treatment consists of modification of activities, use of a thumb brace and occasional icing and then possible use of anti-inflammatory medications. If the pain still persists despite the above treatment a cortisone injection can be helpful. No more than three cortisone injections are recommended per year in any one location.

As a last resort, when conservative treatment has failed, surgical decompression of the tendon by opening up the pulley, a soft tissue over the tendon, can be performed as an outpatient procedure with a small incision. This has a good success rate.