What is Trigger Finger?

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Local swelling from inflammation or scarring of the tendon sheath (tenosynovium) around the flexor tendons causes trigger fingers. These tendons normally pull the affected digit inward toward the palm (flexion). When they are inflamed, they tend to catch where they normally slide through the tendon sheath.

Usually, the trigger finger occurs as an isolated condition because of repetitive trauma. Activities such as gardening, pruning, and clipping are risk factors for trigger fingers. Sometimes, the trigger finger is an associated condition resulting from an underlying illness or medical condition that causes inflammation of tissues of the hand, such as rheumatoid arthritis.

Data presented at the 2005 American College of Rheumatology national meeting suggested that a majority of patients with rheumatoid arthritis have inflammation around the tendons of the palm that could develop into trigger fingers. The trigger finger most often affects the right or left index finger, the digits likely to pull the trigger on a gun.

Symptoms and signs of trigger finger may occur when any of the four fingers of the hand attempts to flex closed while gripping. Instead of a smooth, continual closure, the digit hesitates, then snaps closed (causing a “trigger” effect), and is associated with a stiffness sensation of the digit. Symptoms and signs may occur in more than one digit.

When attempting to extend the digit, a similar hesitation may occur before it “snaps” into full extension. In severe cases, people must manually bring the digits into full extension or flexion because of the stiffness. The closure is frequently associated with pain at the base of the finger on the palm. Sometimes it’s possible to feel a tender nodule in the area of the inflamed tendon. There may be mild swelling in the affected area of the palm.

Triggering can also affect the thumb (trigger thumb, De Quervain syndrome), so many clinicians include the thumb in the diagnosis of the trigger finger.

Primary care doctors, including general practitioners, family medicine physicians, and internists, commonly diagnose the trigger finger. Specialists who treat trigger fingers include orthopedic surgeons, sports-medicine doctors, plastic surgeons, hand surgeons, and rheumatologists. Occupational therapists and physical therapists can be involved in the care of patients with trigger fingers.

Health care professionals diagnose trigger fingers based on the history of “snapping” sensation that the patient experiences, as well as noting in the physical examination that there is tenderness and nodular irregularity of the involved flexor tendon in the palm. Typically, the nodule is not visible but can be felt in the palm. There can be contracture of the affected digit into a bent position.