Almost never recall a precipitating event.
Have a negative Kanavel sign.
Have exquisite pain with finger flexion.
Have no pain when the proximal tendon sheath is palpated.
Present with diffuse fusiform swelling.
Flexor tenosynovitis is a surgical emergency that must be diagnosed promptly by the examining physician and managed aggressively by both the emergency physician and the hand surgeon. Recognizing the classic clinical findings described by Kanavel makes the diagnosis. The four cardinal signs are tenderness over the flexor tendon sheath, symmetric swelling of the finger, pain with passive extension, and a flexed posture of the involved digit at rest.