Don’t beat yourselves up for applying a little home therapy first. It’s a natural response to what may have seemed like a small injury. But as you have discovered, traumatic cuts can lead to infection affecting the flexor tendon sheath (lining) of the fingers.
Several pieces of information are crucial when a physician examines a swollen, painful and tender, hot, and red finger. The first is a good knowledge of finger anatomy, especially of the flexor sheath system of the hand. Studies show there can be quite a bit of variation in the location and configuration of this area from one person to another. There are layers of connective tissue, a pulley system to bend the fingers, the blood vessels, and synovial fluid and the space for synovial fluid. The synovial system is key to providing smooth movement.
Second, the physician must be familiar with all possible causes of these same symptoms. Treatment and the speed at which surgery is considered depends on recognizing a true tendon sheath infection from other diagnoses. The differential diagnosis includes septic arthritis, tenosynovitis, herpetic whitlow, cellulitis, gout, pseudogout, and other hand infections.
Third, knowledge of the four Kanavel signs (named after Dr. Kanavel in 1933 that point to a flexor sheath infection is essential. These include: 1) symmetric (even) swelling of the entire finger, 2) extreme tenderness along the length of the tendon sheath, 3) finger in a slightly bent position, and 4) pain with any attempt by the physician to straighten the finger (passive extension).
Not all four signs have to be present to point to a flexor sheath infection. The two most common findings are tenderness along the sheath and pain with passive extension. It sounds like your husband may indeed have these two symptoms. Patients with other causes of similar symptoms will not have the Kanavel signs associated with flexor tendon infections.
The fourth important item for surgeons to understand when dealing with a potential flexor tendon sheath infection is the nature of bacteria, infection, and matching the most appropriate antibiotic with the bacteria present. Antibiotics are necessary and patients are put on a broad-spectrum antibiotic (one that will kill many different “bugs”) until special tests called cultures are done to identify the specific bacteria present. Then the patient can be switched to a more specific antibiotic. It sounds like this is the stage you are presently at.
And finally, the physician must know what are the treatment options. Conservative (nonoperative) care with intravenous antibiotics, splinting, and elevation must show significant improvement within 48 hours. If there’s been no improvement or the patient gets worse, then surgery to irrigate (clean out) and decompress (take pressure off) the tissue may be necessary.
There is the potential for loss of a finger, which is why early and quick diagnosis and treatment are required. Even without the more serious complications, up to one-fourth of all patients with flexor tendon sheath infections lose their ability to straighten the affected finger. You are in the right place now to get the treatment your husband needs. Take it one step at a time!