Which of the following clinical findings is NOT one of Kanavel’s classic cardinal signs for diagnosing acute pyogenic flexor tenosynovitis?

Explanation:
Kanavel's four cardinal signs of flexor tenosynovitis are: (1) fusiform swelling of the digit, (2) flexed resting posture, (3) tenderness directly along the flexor tendon sheath, and (4) severe pain out of proportion on passive extension. Proximal erythema is a sign of spreading cellulitis or lymphangitis, not a cardinal sign of the tenosynovitis itself. Reference: Green's Operative Hand Surgery.