Trigger finger, or stenosing tenosynovitis, is a common condition affecting the tendons that bend the fingers or thumb. It occurs when the protective tendon sheath becomes inflamed and thickens, often forming a nodule. This nodule struggles to slide smoothly through the narrow A1 pulley, causing a painful catching or locking sensation. When the condition interferes with daily activities, a corticosteroid injection is often recommended as a non-surgical first-line treatment to reduce this localized inflammation. The question of whether the injection itself is painful is a natural concern.
Understanding the Acute Pain During the Injection
The acute pain experienced during a trigger finger injection is typically brief and tolerable, lasting only a few seconds. The procedure begins with the insertion of a fine needle, causing a minor, sharp sting as it passes through the skin. The medication, which contains a corticosteroid and often a local anesthetic like lidocaine, is then injected.
The most significant discomfort usually comes not from the needle stick, but from the volume of liquid injected into the confined tendon sheath space. As the fluid expands the tight area, patients often report intense pressure or a dull ache. While the local anesthetic minimizes post-injection pain, some studies suggest including it can increase the immediate pain felt during the injection.
The goal is to deliver the anti-inflammatory medication precisely to the site of the A1 pulley, which is already a tender spot. The entire process is quick, and medical professionals are trained to perform the injection efficiently to minimize patient distress. The momentary pressure and ache subside almost immediately after the needle is withdrawn, making the acute pain a temporary trade-off for potential long-term relief.
What to Expect Immediately After the Procedure
After the injection, the initial numbing effect of the local anesthetic provides immediate relief, but this sensation is temporary and wears off within a few hours. Patients commonly experience a return of soreness or increased localized pain in the hours and days following the procedure. This delayed discomfort is known as a “steroid flare.”
A steroid flare is thought to be caused by a temporary irritation from the corticosteroid crystals within the tissue before the medication fully dissolves and begins its anti-inflammatory action. This soreness is normal and typically peaks within the first 24 hours, subsiding completely within 48 to 72 hours. To manage this temporary increase in pain, resting the hand and applying a cold compress to the injection site can be helpful. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, are usually sufficient to control the discomfort during this brief period.
Success Rates and Next Steps in Treatment
Corticosteroid shots are a highly effective first-line treatment for trigger finger, offering significant relief for most patients. Studies show that the success rate for a single injection is often reported to be around 66% to 69% for long-term symptom resolution. The thumb tends to have a particularly high success rate, sometimes exceeding 80%.
Relief typically begins within a few days to a week after the injection, as the corticosteroid reduces inflammation in the tendon sheath. If the initial injection fails to provide adequate or lasting relief, a second injection can be considered, which has a high chance of success in patients who did not respond to the first. Patients with co-existing conditions like diabetes may have a lower success rate. If two injections do not resolve the locking or pain, the next step is often a minimally invasive surgical procedure, known as a trigger finger release. While alternatives like splinting and physical therapy exist, injections remain the most common initial interventional approach.