Snapshot A 26-year-old new mother presents to her primary care physician for right wrist pain. She gave birth to a healthy newborn boy 3 months ago who is doing well. She reports pain localized to the radial side of her right wrist. Ulnar deviation of the hand with the thumb clenched in the palm worsens her pain. Introduction Clinical definition stenosing tenosynovial inflammation of the first dorsal compartment tendons abductor pollicis longus (APL) extensor pollicis brevis (EPB) Epidemiology incidence common cause of radial-sided wrist pain demographics women more likely than men adults more likely than children risk factors repetitive wrist motion new mothers and daycare workers caused by frequent lifting of baby assembly line workers secretaries and receptionists golfers and racquet sports players traumatic wrist injury Etiology posttraumatic overuse Pathoanatomy normal anatomy wrist has 6 dorsal compartments organized from radial to ulnar first dorsal compartment contains APL and EPB tendons extensor retinaculum overlies the dorsal compartments pathophysiology extensor retinaculum thickens and swells leading to friction with tendon movement Presentation Symptoms radial-sided wrist pain worse with thumb and wrist motion Physical exam Finkelstein test ulnar deviation of the hand with the thumb flexed in the palm produces pain tenderness at radial styloid along APL and EPB tendons no tenderness proximally along APL and EPB muscle bellies Imaging Radiography indications needed to rule out bony conditions that could be causing radial-sided wrist pain findings will be negative in De Quervain tenosynovitis as the condition is limited to soft tissues (e.g., tendons and fascia) Differential Carpal metacarpal joint osteoarthritis distinguishing factor will demonstrate osteoarthritic changes at the base of the thumb on radiography typically presents over months or years Carpal bone fracture distinguishing factor will demonstrate a fracture line of the radial carpal bones typically presents acutely following trauma Treatment Nonoperative rest, NSAIDs, thumb spica splint, and steroid injection indication most cases will resolve with non-operative management Operative surgical release of the first dorsal compartment indication severe disease that does not resolve following a complete course of non-operative management Complications Superficial radial nerve injury surgical complication due to the superficial radial nerve passing directly over first dorsal compartment supplies sensory function along the radial thumb