De Quervain’s tenosynovitis is an inflammatory conditions of the tendons of the wrist that reside on the side of the thumb. These tendons are the abductor pollicis longus and extensor policis brevis.  The inflammation is the result of trauma from repetitive motion at the wrist such as shaking hands or turning a screwdriver.  Symptoms include pain, tenderness and swelling at the base of the thumb.  The tendon may “lock” or “trigger” causing a sticking sensation during motion.  The condition is diagnosed based on history, clinical findings and a provocative test known as the Finkelstein test.  The test is performed by having the patient fold his thumb into the palm and then flex the wrist away from the thumb.  Sudden severe pain during this motion is suggestive of De Quervain’s tenosynovitis.  There are several other conditions which can be confused with De Quervain’s such as arthritis of the small joints of the hand, cervical disc disease, gout and cheiralgia paresthetica.  Treatment includes physical therapy, heat, ice, splinting and injections into the area.  Patients who do not improve with conservative modalities may be a candidate for surgical intervention.