Which nerve supplies sensory innervation to the dorsum of the hand near the base of the little finger, implicating ulnar involvement?

• A. Radial nerve
• B. Ulnar nerve
• C. Median nerve
• D. Musculocutaneous nerve

Answer: (B)

The area described—the dorsum of the hand near the base of the little finger—is supplied by the dorsal cutaneous branch of the ulnar nerve. This region lies on the medial (ulnar) side of the hand, and its sensation points to ulnar nerve involvement. The radial nerve covers the lateral part of the dorsum (thumb side), and the median nerve mainly supplies the palmar surface of the lateral three-and-a-half digits (and their distal dorsal tips), while the musculocutaneous nerve provides sensation to the lateral forearm, not the dorsum of the hand. So sensing this specific patch of skin implicates the ulnar nerve.