A 52 year-old patient presents with a two month history of intermittent pain in their wrist and forearm on both sides, in addition to numbness and tingling in the thumb and index fingers after prolonged use. During the examination, the advanced practice registered nurse (APRN) notes both a positive Tinel's and Phalen's test. What is the most appropriate primary diagnosis based on these findings?

Wrist and hand neuropathic symptoms require careful differentiation between compressive nerve disorders, inflammatory conditions, and structural injuries. Carpal tunnel syndrome is caused by compression of the median nerve as it passes through the carpal tunnel at the wrist. It commonly presents with numbness, tingling, and pain in the thumb, index, and middle fingers, often worsened by repetitive hand use. Positive Tinel’s and Phalen’s tests are key clinical indicators supporting this diagnosis. Rationale: A. Flexor tenosynovitis (trigger finger) involves inflammation and thickening of the flexor tendon sheath, leading to painful locking or catching of a specific finger during flexion and extension. It does not typically produce bilateral numbness or tingling in the median nerve distribution. Additionally, Tinel’s and Phalen’s tests are not diagnostic for trigger finger, making it inconsistent with the findings in this case. B. Carpal tunnel syndrome is the most likely diagnosis because it results from compression of the median nerve within the carpal tunnel. This condition produces paresthesia in the thumb, index, and middle fingers, often worsened by repetitive wrist activity or prolonged flexion. Positive Tinel’s and Phalen’s tests strongly support median nerve entrapment, confirming this as the primary diagnosis. C. Psoriatic arthritis is an inflammatory arthropathy associated with psoriasis and can involve distal interphalangeal joints, but it typically presents with joint swelling, stiffness, and skin lesions rather than isolated nerve compression symptoms. While it may cause hand pain, it does not produce classic median nerve distribution paresthesia or positive Tinel’s and Phalen’s signs. D. Occult scaphoid fracture usually presents after trauma with localized wrist pain, tenderness in the anatomical snuffbox, and possible swelling. It does not typically cause bilateral symptoms or nerve compression signs such as numbness in specific fingers. The absence of trauma history and the presence of neuropathic findings make fracture an unlikely diagnosis in this scenario.