deQuervain's Tenosynovitis
Signs and Symptoms

2) Signs and Symptoms - Patients typically complain of the gradual onset of pain over the area indicated above by the red dot (over the radial styloid, an area of a bone in the forearm) when they use their thumb on the affected hand.  The sufferer may relate that the pain has gradually increased over that past few weeks or months.  The patient experiences difficulties with gripping and pinching, and in severe cases, the affected hand may be too painful to use.  The pain may radiate into the thumb, or up into the forearm or shoulder.  Examination of the affected area reveals thickening and tenderness.  A test commonly used to evaluate the presence of this disease is Finkelstein's test;  the patient is instructed to grasp the thumb of the affected hand with the other fingers and actively pull the thumb towards the small finger.  Sharp pain will be elicited over the area indicated by the red dot if the patient suffers from deQuervain's tenosynovitis.  This condition must be differentiated from arthritis at the base of the thumb.  If the disease is allowed to progress without treatment, it is possible that fibrosis within the tendon sheath may result and a clinical picture similar to trigger finger (see other section) may result with limited motion.  Ultrasound examination has recently been used to confirm the diagnosis and can be used to follow up after treatment.

- Possible causes -  The precise cause of deQuervain's tenosynovitis is unknown.  It is thought that excessive friction from overuse of the thumb and wrist (excessive and repetitive gripping and grasping actions) may be a factor, leading to thickening of the tissues in the compartment housing the APL and EPB tendons.  For example, cases have been described in bricklayers, those who sew, piano players, fly fishermen, and golfers.  It has also been hypothesized that the condition in some cases may be associated with acute injury to the involved area (direct blow to the forearm or wrist, falling on the thumb).  However, most cases appear to be associated with a more monotonous, "chronic trauma" picture as mentioned above.