Among different forms of arthritis, psoriatic arthritis is an inflammatory type of disorder of joints related to psoriasis. A person with psoriatic arthritis experiences inflammation and pain in joint as well as thick, red and patchy skin. Being an autoimmune disease, overactive immune system of the body is one of the major causes of psoriatic arthritis. This disease can affect both men and women equally and the people between the age group of 30-50 are more prone to this disease. About 30% of people having psoriasis can suffer by the psoriatic arthritis.

Though medical science is not clear about the exact causes of psoriatic arthritis, this disease is supposed to be developed from a combination of hereditary (genetic) and environmental factors. More than 40% of people with family history of arthritis or psoriasis are at the higher risk of developing psoriatic arthritis. It is suspected that genes on chromosome 6p are likely to cause both psoriasis and psoriatic arthritis.

Some environmental factors and some bacterial, viral or fungal infections are among the important causes of psoriatic arthritis. Usually, the immune system of the body produces certain cells that attack the infections. In autoimmune disease like psoriatic arthritis, the immune cells attack the joints which may lead to an inflammation.    Koebner phenomenon in which psoriasis develops at the site of trauma can cause psoriatic arthritis.

Besides this, various immunological abnormalities can be included in possible causes of psoriatic arthritis. Both B and T cells, chemokines and cytokines can cause development and prolongation of inflammation due to psoriatic arthritis. Cytokine is considered as an important triggering factor while chemokines and cytokines cause the development of inflammation which leads to tissue destruction in psoriatic arthritis. There may be elevated levels of tumor necrosis factor in tissue and blood samples of the patient with psoriatic arthritis.

In some cases, bacterial, viral or fungal infections act as a triggering factor for psoriatic arthritis. Some of the risk factors for psoriatic arthritis are skin injuries, infections especially streptococcal infections, stress, reactions to vaccines or medications, alcohol and poor nutrition, overexposure to sun, long-term exposure to irritating chemicals such as paint thinners and disinfectants.

Having psoriasis is the greatest risk factor for psoriatic arthritis. A person between the age-group of 30-50 and having family history of psoriatic arthritis is at the higher risk of developing this disease. Besides this, a person with HIV infection is more prone to this disorder.