Difference between Psoriatic and Rheumatoid Arthritis

There are lots of types of arthritis. But in general, this inflammation joint problem is divided into two major types; rheumatoid arthritis (RA) and osteoarthritis. How about psoriatic arthritis (PsA)? As the name suggests, this type is a consequence of health condition called psoriasis (a chronic skin problem).

To clearly understand the difference between psoriatic and rheumatoid arthritis, it’s better to understand the cause and the way of how they occur.

How does RA develop?

Although the exact cause of RA is not fully understood yet, but it is thought as an autoimmune health condition in which the immune system mistakenly attack its own healthy cells or tissues. Normally, the body’s immune system is essential to help fight against foreign substances such as harmful viruses or bacteria.

But if you have RA, the body’s immune system mistakenly attacks the joints (particularly the membrane’s linings that surround the joints called synovium), resulting inflammation that can cause joint damage.

There is still no answer of how and why the immune system attacks the wrong targets such as synovium – though genetics appear likely. Some external factors such as bacterial or viral infection may also have a role in triggering the disease.

In some cases, RA doesn’t only affect joints but it may also affect other organs such as lung and heart. It seems that having RA increases the risk of lung disease and heart problems.

In other words, the risk of disability is not the single issue you need to worry if you have RA. Other complications also should be concerned as well.

The diagnosis for the disease is so crucial. Earlier diagnosis followed with prompt treatment is better for the prognosis and outlook of the problem.

How does PsA occur?

As mentioned before, it is a kind of chronic inflammatory arthritis associated with psoriasis ‘a lifelong skin problem’, which is also believed to run in families. Having a family history of PsA or psoriasis can put you at greater risk of developing the same condition.

Psoriasis itself is a skin problem characterized by scaly, thick patches with silver-white in color. It is one of common chronic skin disorders. In the U.S, it affects about 2 % of the population.

image_illustration167The exact cause of psoriasis is not known, the same goes for PsA. However, they are also thought as a consequence of the body immune system abnormality.

The disease occurs when the immune system starts to attack the wrong targets such as healthy tissues and cells. This abnormality leads to inflammation & damage in the joints as well as rapidly production & movement of new skin cells to the skin surface.

And again, the exact answer for the cause of how this process starts is not fully understood. It seems that both external factors and genetics play a role.

Unlike in RA where the main target is only joints – in PsA, there are two major targets of the disease; joints and skin.

Typically, PdA is diagnosed after psoriasis. But in a few cases, PsA can occur before psoriasis.

What are other differences?

For clearly diagnosis, there are some procedures and tests needed to distinguish between PsA and RA. For instance, a blood test is often used to make diagnosis of PsA – this test can help rule out other health conditions such as RA.

So the final diagnosis is not made on your own. However, there are some differences between psoriatic and rheumatoid arthritis. The following is a helpful table for the summary of these differences: