De Quervain's Tenosynovitis is a condition causing pain in the base of the thumb and side of the wrist. It affects some of the tendons that extend the thumb, and they become irritated in the fibrous tunnel they pass across the back of the wrist.
Most cases of De Quervain's have no obvious cause but there are some associations with changes in repetitive activities. New mothers often get De Quervain's with repeated lifting of babies, and there are also some occupational causes.
People with De Quervain's complain of pain along the line of the tendons at the base of the thumb that extends up the wrist. This is made worse by movement of the thumb or wrist.
Tests / Diagnosis
There are some specific clinical tests that are very useful for the diagnosis of De Quervain's and additional investigations are rarely necessary. Occasionally an ultrasound can confirm the diagnosis.