Who Gets Psoriatic Arthritis & Why?
Psoriatic arthritis affects approximately one-tenth of 1% of North Americans:
- It is most common in Caucasians, with an incidence rate of 2%; it is uncommon in Asians and African blacks
- Equal numbers of men and women suffer from the disease, except:
- In cases where only the fingers are affected, primarily experienced by males
- In cases where joints on both sides of the body are affected, similar to rheumatoid arthritis, primarily experienced by females
- In cases of spinal involvement, where male cases outnumber female cases 3:1
- Typical age of initial onset of PSA is age 30-55, whereas peak age of onset for psoriasis itself is age 5-15. There can be late stage onset as well.
The cause of psoriatic arthritis (and psoriasis in general) is unknown. However, studies strongly suggest genetic predisposition towards PSA. First-degree relatives of PSA sufferers are believed to have a 50% likelihood of developing some form of arthritis in their lifetime.