There are several key signs and symptoms practitioners look for when identifying rheumatoid arthritis in the hand and wrist. Some are subtle, while others, such as hand deformities, are more obvious.
Signs and Symptoms of Hand RA
Rheumatoid arthritis (RA) is a systemic inflammatory disease that often affects small joints. A diagnosing physician will examine a patient’s hands, feet, and any other joints—large or small—that the patient reports as painful. A physician will also ask about other symptoms, including fatigue, nausea, and fever.
In the hands, a physician may look for:
Hand joint swelling
RA triggers an inflammatory response that results in a buildup of synovial fluid as well as a thickening of joint tissue in fingers and wrists. The swollen joints may feel tender to the touch.
In contrast to osteoarthritis and many other forms of arthritis, rheumatoid arthritis usually affects both sides of the body equally. For example, inflammation may occur in both the right and left wrists at the same time. Symmetrical inflammation can make mild hand swelling difficult to notice because there is no “normal” hand with which to make a comparison.
Difficulty making a fist
A decrease in the hand joint’s flexibility and strength may make it hard to squeeze the fingers and thumbs into a fist. The authors of one clinical study suggest that difficulty making a fist may be a predictor of developing rheumatoid arthritis.1
Pain and stiffness
People with rheumatoid arthritis often complain of localized pain in the wrists, large knuckles (metacarpophalangeal joints), and/or middle knuckles (proximal interphalangeal joints).
Stiffness is often worse in the morning or after periods of inactivity. Simple tasks, such as getting dressed, using a smartphone, or preparing food may become difficult.
Flushing of the skin
The skin over the wrist(s) and knuckle(s) may become red and warm to the touch.
Carpal tunnel syndrome
People with rheumatoid arthritis may experience tingling and numbness in their hands and fingers. These symptoms are the result of swelling and inflammation in the carpal tunnel, a narrow channel between bones and ligaments within the wrist through which a major nerve passes.
This major nerve, called the median nerve, and its branches provide feeling to the thumb, index finger, middle finger, and half of the ring finger. When the space in the carpal tunnel decreases, the median nerve becomes squeezed, and a person may feel weakness, numbness, and/or tingling in the thumb, index, middle, and ring fingers.
Presence of rheumatoid nodules
Hard, rounded bumps made of inflammatory tissue may develop underneath the skin near the affected hand joints. These nodules are not usually painful and may shrink with the use of RA medications. Nodules can develop on fingers and wrists and frequently develop on forearms and elbows.2
Malalignment of one or more finger joints
Over time, the destruction of bone and joint tissue may cause fingers and thumbs to become deformed. While the risk of hand deformities is significant, they are not inevitable.
Hand Deformities from Rheumatoid Arthritis
Evidence suggests that hand deformities commonly occur in the first year of rheumatoid arthritis if it goes untreated.3 Moreover, people who experience hand deformities in the first year tend to have more severe cases of the disease.3
In some cases, hand deformities can be treated. In addition, new rheumatoid arthritis medications have reduced the likelihood that rheumatoid arthritis will cause permanent deformities.
The most common finger and wrist deformities are described below.
The flexor tendons of the hand allow fingers to bend. When a flexor tendon is inflamed it is called tenosynovitis. Tenosynovitis can cause the middle knuckle to become stuck in a bent position. This condition is called trigger finger.
This hand deformity, sometimes called buttonhole deformity, occurs when the middle knuckle (PIP joint) becomes stuck in a bent position while the large knuckle (MCP joint) and outermost knuckle (DIP joint) hyperextend.
Swan's neck deformity
Swan’s neck deformity occurs when the outermost knuckle (DIP) abnormally flexes, while the middle knuckle (PIP joint) hyperextends. This results in the finger resembling a swan's neck.
Sometimes called duckbill or Z-thumb, hitchhiker’s thumb occurs when the thumb’s large knuckle (MCP joint) abnormally flexes while the top knuckle (IP joint) hyperextends. Some people think this abnormal bending resembles a Z-shape.
Also called ulnar drift, ulnar deviation refers to when the fingers angle away from the thumb. This deformity occurs when the large knuckles (MCP joints) are so damaged that the fingers begin to dislocate and drift sideways, toward the ulna bone in the forearm.
More than one hand deformity can develop at the same time.4 For example, a swan’s neck deformity can develop in a middle finger and trigger finger deformity in an index finger.