A 34-year-old woman presents to her primary care physician with a 3-week history of pain along the radial side of her right wrist. She recently gave birth and notes that the pain is most intense when she is lifting her infant from a crib. She denies any history of acute trauma, fever, or joint swelling. Past medical history is negative. On physical examination, there is mild swelling and exquisite tenderness over the radial styloid process. The patient is asked to tuck her thumb into her palm and deviate her wrist toward the ulnar side, which reproduces the sharp pain. Strength and sensation in the hand are otherwise intact.
Which of the following is the most likely diagnosis?
The correct answer is:
B) De Quervain tenosynovitis
The patient is presenting with De Quervain tenosynovitis, a common stenosing tenosynovitis involving the tendons of the first dorsal compartment of the wrist. Specifically, it involves the abductor pollicis longus (APL) and the extensor pollicis brevis (EPB) tendons as they pass through a fibrous sheath over the radial styloid. It is classically seen in new mothers due to the repetitive thumb abduction and ulnar deviation required to lift a baby. The physical examination maneuver described is the Finkelstein test, which is highly characteristic of this condition. By tucking the thumb and performing passive ulnar deviation, the inflamed tendons are stretched against the radial styloid, reproducing the patient's pain.
Answer choice A: Carpal tunnel syndrome, is incorrect. Carpal tunnel syndrome involves compression of the median nerve and typically presents with numbness and tingling in the first three and a half digits, often worse at night. It does not cause localized tenderness over the radial styloid or a positive Finkelstein test.
Answer choice C: Intersection syndrome, is incorrect. While intersection syndrome involves the wrist extensors, the pain is located more proximally (about 4–6 cm from the radial styloid) where the APL and EPB cross over the radial carpal extensors. It is more common in rowers or weightlifters.
Answer choice D: Osteoarthritis of the first carpometacarpal (CMC) joint, is incorrect. While this causes radial-sided wrist pain, the tenderness is usually localized more distally at the base of the thumb (the CMC joint) rather than the radial styloid. A positive "grind test" (axial loading and rotation of the thumb) would be more typical than a positive Finkelstein test.
Answer choice E: Scaphoid fracture, is incorrect. Scaphoid fracture typically follows an acute injury, such as a fall on an outstretched hand, and presents with tenderness in the anatomical snuffbox. This patient's history of repetitive lifting and a positive Finkelstein test point toward a tendon pathology rather than a bone fracture.
Key Learning Point
De Quervain tenosynovitis is a stenosing tenosynovitis of the abductor pollicis longus and extensor pollicis brevis tendons. It is diagnosed clinically using the Finkelstein test and is often associated with repetitive thumb use, such as lifting a child. Initial management includes a thumb spica splint, NSAIDs, and activity modification.
