The joints experience a significant amount of stress and strain throughout life. From bearing the body weight to endlessly moving in daily activity, joints are prone to a range of injuries and diseases as is the case with any part of the body. Joint pain is known as arthralgia and may affect any joint in the body. It can be associated with other signs and symptoms like stiffness, swelling of the joint, redness of the overlying skin and decreased mobility. Pain may occur in small or large joints only or in both simultaneously. Similarly, the pain may be isolated to a single joint (monoarticular pain) or affect several joints at the same time (polyarticular pain). Some types of injury and certain diseases tend to affect specific joints, while at other times the disorder may not be as discriminatory and there is generalized arthritis.
Joints of the Fingers
The hand has 27 bones – 8 in the wrist (carpus), 5 metacarpals in the hand itself and 14 phalanges that make up the fingers. Between these bones are several joints of different types. The fingers itself are made up of 3 phalanges each, except for the thumb which has two.
The proximal phalanges articulate with the hand bones (metacarpals) – these joints are known as the metacarpophalangeal joints. Between each phalynx is a joint that is known as the interphalangeal joints. Joints are made up of the two articulating surfaces of the bones which is capped with cartilage, lined by a synovial membrane and surrounded by a fibrous capsule. Various ligaments secure the joints and ensure that the articulating surfaces of the bones do not slip from its normal position and orientation. Read more on finger joints.
The common term ‘knuckle’ is often used to describe the metacarpophalangeal and interphalangeal joints. The first knuckle is the metacarpophalangeal joints while the interphalangeal joints are referred to as the second or third knuckles or minor knuckles. The use of the term ‘knuckles’ may vary but is intended to refer to the finger joints.
Painful Joints and Inflamed Joints
Inflammation is a physiological response to injury characterized by four cardinal features – pain, swelling, redness and heat. When a joint is inflamed, it is referred to as arthritis. However, pain in the joints may occur without inflammation and in this case it is simply referred to as arthralgia. However, the term ‘arthralgia’ is broad and can still be attributed to pain associated with inflammation.
Pain may be of the joint itself (intra-articular) or around the joint (peri-articular). Joints do not occur in isolation – it is formed by articulating surfaces of bones, supported by ligaments and movement is due to the action of associated muscles and its tendons. Therefore it is possible that joint pain may sometimes not be pain arising from the joint itself but the other structures may be responsible for the pain without any involvement of the joint.
Causes of Painful Finger Joints
Trauma and Strain
Finger pain after trauma to the hand, and particularly the fingers, is expected and depends on the severity of the injury. Minor injuries may cause acute pain that last for a few minutes or hours and resolves with little more than soreness for a few days particularly when the joint is used.
However, more severe injuries can damage structures within the joint or around it and lead to persistent finger pain that may progressively worsen over time. This mainly occurs when there is tissue damage and associated complications following the injury like in synovitis, meniscal tears, fibrocartilage damage, bleeding within the joint (hemarthrosis), tendinitis and bone fractures. Pain associated with trauma rarely affects more than a single joint at a time or several fingers joints of the same hand (monarticular). Entry of a foreign body into the joint may cause both trauma to the area and an immune-mediated reaction.
Overuse or strain is often dependent on the occupation or recent activities. It may arise with excessive writing, typing, fine craft work, prolonged use of game controllers, mobile phone texting or lifting heavy objects using primarily the fingers to bear the weight. With long term activities, the fingers often adapt to these scenarios.
Arthritis is a broad term for any type of joint inflammation. However, when the fingers are concerned, rheumatoid arthritis should always be considered particularly if it is associated with :
- Morning stiffness and pain that is bilateral
- Stiffness that eases with movement
- Nodules or joint deformities
The finger joints are a common site for rheumatoid arthritis while involvement of the thumb should raise concerns about osteoarthritis (OA).
Other types of arthritis includes :
- Crystal-induced arthritis – accumulation of uric acid crystals or calcium salts.
- Septic arthritis – bacteria, viruses or fungi may gain entry into the joint.
- Reactive arthritis (Reiter’s syndrome) – autoimmune response triggered by an infection usually outside the joint.
- Psoriatic arthritis – arthritis associated with psoriasis vulgaris (skin disease).
- Juvenile idiopathic arthritis – arthritis in children due to unknown causes.
It is important to note that some of these types of arthritis are not frequently seen in the finger joints but need to be considered as possible causes.
Septic arthritis may be due to bacteria, viruses or fungi and tends to arise after trauma to the area (usually bacterial) or with systemic infections particularly in immunocompromised patients. In these instances the pathogen gains entry into the joint. At times there may be dissemination where pathogens involved in an infection at one site may travel via the bloodstream, lymph or directly infiltrate from neighboring sites to enter the joint. However, joint pain with/without inflammation may arise with other infections that may not involve the joint directly. Usually more than one joint is involved.
- Rheumatic fever
- Bacterial endocarditis
- Hepatitis B or C
- Glandular fever
- Tuberculosis (TB)
Joint pain may also arise after an infection (post-infective) as is seen in reactive arthritis and rheumatic fever.
In autoimmune disorders, the immune system is targeted against the body’s tissue. This can be at specific tissues like the joint, its lining or bursa, or affect any tissue indiscriminately. Other types of immune responses include hypersensitivity where the immune system reacts abnormally to an otherwise harmless substance and causes inflammation of various tissues. Immune-related disorders that may account for finger joint pain include :
- Rheumatoid arthritis
- Reactive arthritis
- Systemic lupus erythematosus
- Serum sickness
- Enteropathic arthritis – joint pain and inflammation seen with inflammatory bowel disease.
Benign tumors or cancer of the bones of the joint or the joint tissue itself may also be responsible for finger joint pain. Overall, tumors of the joint are not common.