What is viral arthritis?
Viral arthritis is inflammation of the joint caused by the presence of a virus. While viral arthritis can occur with a viral infection, it is not always the virus itself that is attacking the joint tissue and causing inflammation. Instead it may be the immune system that targets the joint lining due to the production of antibodies against the virus. Therefore viral arthritis can even arise with the use of some vaccines. Viral infections itself rarely cause permanent damage to the joint. The arthritis is usually acute. However, the ongoing immune response even after the infection resolves may lead to joint complications which need to be assessed on an ongoing basis in chronic arthritis.
Viral Arthritis Meaning
There are many different types of arthritis, which is a broad term to refer to inflamed joints. Some of the more common types of arthritis like rheumatoid arthritis arises when the immune system attacks the joint lining. Other types like septic arthritis arises with a bacterial infection of the joint. Osteoarthritis is more of a bone problem involving the ends of the bone and cartilage that are involved in the joint. Viral arthritis occurs with the presence of certain virus.
Viruses are one type of pathogen that can cause an infection in the body. Some viruses have an affinity only for certain cells. Other viruses can attack any cell. The presence of the virus and its injury to tissue elicits the process of inflammation. Blood vessels become leaky, fluid enters the tissue spaces and immune cells can rush to the site to fight the virus. This is seen as the features of inflammation like swelling, pain, heat and redness of the skin over the affected joint. Most of the viral infections that cause arthritis resolve on its own, often without even any treatment and in a short period of time – acute. However, the immune effects that may continue thereafter can last for long periods – chronic.
When a virus enters the body, the immune system produces protein molecules (antibodies) that are specific to the proteins on the viral surface (antigens). In this way antibodies circulating in the bloodstream can quickly attach to the virus and direct the other components of the immune system to identify the virus and destroy it. However, sometimes these antibodies lodge in the lining of the joints (synovium) and the immune cells then attack the joint lining. Other common types of arthritis like rheumatoid arthritis may have a viral origin although the majority of cases may be due to genetic disruptions of the immune system.
Viral Arthritis Causes
There are number of different viruses that can cause viral arthritis. This includes :
- Cytomegalovirus (CMV)
- Hepatitis A, B and C
- Herpes simplex virus (HSV)
- Human immunodeficiency virus (HIV)
- Human parvovirus
- Human T-lymphotropic virus
- Rubella and the vaccine
- Varicella zoster virus
Some of these viruses very rarely cause arthritis. It is also important to note the difference between arthralgia and arthritis. Arthralgia is joint pain and it is a common symptom of many viral infections. Arthritis on the other hand is joint inflammation and while pain is also a feature of inflammation, not all viral infections will lead to arthritis.
Viral Arthritis Symptoms
Viral arthritis may present with a combination of infectious symptoms and viral symptoms.
The symptoms of arthritis due to a virus are not dissimilar from arthritis associated with any other mechanism. The main symptoms include :
- Swollen joint
- Joint pain (arthralgia)
- Reduced range of motion
- Heat and redness of the joint which may not always be evident.
The symptoms of the infection either precede arthritis or are present at the same time as the arthritis symptoms. Sometimes the infectious symptoms resolve but the arthritis symptoms persist for a long period thereafter. It is more confusing when the infectious symptoms appear and resolve and the arthritis symptoms only start up a long time afterwards. In these instances, the connection between the infection and the arthritis is not immediately made unless further testing is undertaken.
The symptoms of the infection can be diverse since many different types of viruses can cause arthritis. These symptoms may include :
- Runny nose
Viral Arthritis Diagnosis
Diagnosis of viral arthritis is not immediately made solely upon clinical examination and medical history. There are other more common causes of arthritis. If the arthritis is acute, it is simply treated symptomatically until the infection resolves. Further diagnostic tests are not considered specifically for the arthritis. However, chronic arthritis does warrant further testing to evaluate the extent of the inflammation, damage to the joints and bones and the possible cause.
- Complete blood count may indicate an infection but not the cause of the infection.
- Specific antigen and antibody testing can identify the exact type of virus.
- X-ray and CT scan to detect the extent of the inflammation and changes to the joint.
Viral Arthritis Treatment
Acute viral arthritis may resolve with the infection. It is usually mild and symptomatic relief may be all that is necessary if a patient is experiencing significant discomfort from the arthritis symptoms. Chronic arthritis will have to be assessed later and treated accordingly once the infection has resolved. However, with chronic infections like HIV, the treatment of the infection is ongoing and more aggressive measures may be needed to treat the arthritis.
Some of the medication used in the treatment of viral arthritis includes :
- Non-steroidal anti-inflammatory drugs (NSAIDs)
- Analgesics (painkillers)
- Antivirals or antiretrovirals (ARVs)
There are several other treatment options that may be considered when one or more of the medication above fail to yield the desired results. The medication or combination of drugs depends largely on the viral infection associated with the arthritis. Some medication may be contraindicated in that it can suppress immune defenses which is not desirable in certain conditions where the immune system is already compromised, like with HIV infection.
Surgical drainage (aspiration) is usually not necessary unless there is pus associated with septic arthritis. In rare instances where the fluid accumulation within the joint is excessive and not resolving with medication, fluid drainage from the joint may be necessary.