What is Arthralgia?
Arthralgia is the term for pain in the joint(s). It should not be mistaken with arthritis which is inflammation of the joints. Arthritis also presents with the other signs of inflammation like swelling, redness and/or heat. Joint pain is almost always seen in arthritis since pain is another feature of inflammation. However, not every case of joint pain will be accompanied by joint inflammation and associated features like swelling, redness or heat may not be present.
Signs and Symptoms of Arthralgia
Joint pain is a symptom and not a condition on its own. Identifying the character of the pain; other signs and symptoms that present; trigger, exacerbating and relieving factors; and the site of the pain will assist with isolating a possible cause.
Pain and movement
Mobility of the affected joint may be limited, sometimes due to swelling and degenerative changes, or restricted as a result of the exacerbation of pain. In arthralgia without swelling, or involvement of surrounding structures like the bursa, muscles, tendons, ligaments or bone the range of motion may still be normal.
Pain in the joints may be inflammatory or non-inflammatory. In inflammatory conditions, the pain is present both at rest and upon movement, while with non-inflammatory causes of athralgia, the pain may ease at rest and exacerbate upon movement. Stiffness of the joints should also be noted as it is often a sign of an inflammatory response and often eases with movement as is seen in rheumatoid arthritis.
Pain in or around the joint
It is also important to take note of whether the pain is within the joint itself (intra-articular) and localized, or diffuse thereby possibly originating from surrounding structures like to muscles (per-articular). Referred pain is when the pain originates from another site but radiates to the joint.
Pain in one or more joints
Arthralgia may affect one joint only (monoarticular), 2 to 4 joints (oligoarticular/pauciarticular) or 5 joints and more (polyarticular). The pain may move from one joint to another (flitting) and concomitant signs like a fever and rash is may also be present.
Types of Joint Pain
Joint pain (arthralgia) can be categorized as :
- Inflammatory or non-inflammatory
- Swelling of the joint, along with redness of the overlying skin and warmth of the area, are signs of an inflamed joint (arthritis). The absence of swelling, redness and warmth of affected joint, despite the pain, is an indication of non-inflammatory joint pain.
- Mono-, oligo-, polyarticular
- Monoarticular refers to one joint, whereas oligoarticular refers to two to four joints and polyarticular is more than four joints (five or more). This approach is often adopted for arthritis.
- Generalized or localized
- Generalized joint pain refers to diffuse pain, often with a regular change in the location of the joint pain (flitting) and may affect multiple joints simultaneously. Localized joint pain refers to pain within a specific joint or joints.
Causes of Joint Pain
Trauma and Strain
This usually results in localized joint pain, which is often inflammatory and is due to injury or strain of a specific site. However generalized joint pain may be seen after trauma like high impact collisions (road traffic accidents). Weight gain, which causes a change in the center of gravity, as well as an altered gait due to an injury, may also cause joint pain as these areas are strained due to the change in posture.
Pain is often due to inflammation of :
- Tendons – tendonitis like achilles tendonitis, rotator cuff (shoulder) – supraspinatus tendonitis
- Bursa – bursitis
- Enthesis (where muscles attach at a bone) – enthesopathies like tennis or golfer’s elbow
- Nerve – entrapment like in carpal tunnel syndrome
Joint pain is a common symptom of certain systemic infections, is usually non-inflammatory and affects multiple joints. Reactive arthritis may also occur as a result of an infection elsewhere in the body or after an infection (post-infective like in rheumatic fever) but is usually inflammatory in nature and affects multiple joints.
- Viral infections like chickenpox, hepatitis (especially B and C), glandular fever, mumps, rubella.
- Bacterial infections like tuberculosis, subacute bacterial endocarditis, Lyme disease, septicemia.
- Fungal infections
This is usually inflammatory as microorganisms may invade the joint following trauma, from a neighboring site or less frequently through dissemination from a distant site. This is known as septic arthritis. Usually only one joint is affected unless there was trauma of multiple joints and the invading pathogens had the opportunity to infect multiple areas.
While bacteria, mycobacteria, viruses and fungi may cause septic arthritis, bacteria are most commonly involved. Neisseria gonorrhoeae, Staphylococcus aureus and streptococci are the more common bacteria responsible.
Autoimmune causes often results in inflammatory joint pain (arthritis), usually affecting more than one joint although it may initially present with inflammation of a single joint.
Examples of autoimmune causes may include :
- Rheumatoid arthritis
- Systemic lupus erythematosus (SLE)
- Ankylosing spondylitis
- Systemic sclerosis
- Sjögren’s syndrome
This typically results in non-inflammatory joint pain which often affects two or more joints although at times pain may only be present in a single joint. Typically the pain is worse upon movement and eases with rest. Osteoarthritis is one of the main degenerative causes of joint pain. Although referred to as arthritis, the typical features of inflammation are often absent, except for pain.
Bone and cartilage tumors usually cause non-inflammatory joint pain although some rapidly growing musculoskeletal cancers may result in joint inflammation along with pain. Usually only one joint is affected although metastases may affect multiple joints simultaneously. Systemic effects of a tumor at a distant site may also result in joint pain and often affects more than one joint.
- Primary – osteosarcoma, chondrosarcoma.
- Secondary (metastatic) – spread from distant sites like the lung, breast or prostate.
Accumulation of crystals around or in a joint that causes inflammation and pain. This is seen with gout where there is a build up of urate crystals around the joint or in pseudogout where calcium pyrophosphate dihydrate (CPPD) crystals affect the joint lining. Only one joint is usually affected.
A rebound joint pain is often seen when chronic corticosteroids are stopped (withdrawal). Certain medication like angiotensin-converting enzyme (ACE) inhibitors, glibenclamide, methyldopa, ciclosporin, isoniazid and barbiturates may cause arthralgia or arthritis. It may be inflammatory or non-inflammatory in nature, typically affects more than one joint although sometimes pain in only a single joint is present.
- Hypermobility syndromes, where joints are lax and hypermobile (extending beyond the normal range of motion) and typically results in joint pain (arthralgia) and muscle pain (myalgia). More than one joint may be hypermobile and pain is typically seen in one joint at a time, although more active people with hypermobility syndromes may complain of pain in multiple joints.
- Fibromyalgia syndrome usually results in generalized and typically non-inflammatory joint pain. Although infections, emotional stress and genetic factors have been implicated, the exact cause is unknown. More than one joint is usually affected and the location often changes (flitting).
- Hemarthrosis is a result of coagulation (blood clotting/bleeding) disorders where there is bleeding into the joints. Usually only one joint is affected at a time.
- Hemachromatosis is an inherited condition where there is an iron overload and one of the symptoms is joint pain. Often more than one joint is affected and deformities of the joint may also be present.