Psoriatic arthritis (PsA) is a disease that causes inflammation in the joints and tendons. This leads to joint pain, stiffness, and swelling. Experts think PsA affects about 1 million people in the United States. However, that number is likely higher since PsA often is misdiagnosed for another health condition or goes undiagnosed.1
Experts have identified 3 clear risk factors for PsA:2-4
- Psoriasis
- Family history
- Age
Psoriasis
People with psoriasis are at an increased risk of developing PsA. Psoriasis is a skin condition that is marked by red, scaly, itchy patches that form on the body.2-4
PsA occurs in up to 30 percent of people with psoriasis. Nearly all people with PsA also have psoriasis. In most people, the skin disease generally develops before the joint disease. However, PsA develops before the skin lesions of psoriasis in about 13 to 15 percent of cases.3,4
Some studies have shown that the more severe a person's psoriasis is, the greater their risk of developing PsA. However, if someone has severe psoriasis, it does not mean they will have severe PsA.2,3
The location of a person's psoriasis may put them at an increased risk of developing PsA. Areas that have been linked to an increased risk of PsA include:2,3
- Scalp lesions
- Damage to the nail beds (nail dystrophy)
- Lesions between the buttocks (intergluteal lesions) or around the anus (perianal lesions)
Family history
Both psoriasis and PsA run in families. Research suggests that both conditions have a strong genetic basis.2,3
If you have a first-degree relative who has PsA, your risk of developing the disease is about 49 times greater than someone with no family history of the condition. First-degree relatives include siblings and parents.2,3
Age
PsA occurs more often in adults ages 35 to 55. However, it can occur in children, too. This rarer type of PsA is referred to as juvenile PsA. It typically develops in children ages 9 to 11.2,3
Other risk factors
There are other risk factors being studied that may shed light on the general population’s overall PsA risk. They include obesity and smoking.2
Obesity
Some studies have shown a link between body mass index (BMI) and the risk of PsA in people with psoriasis. Obesity also may reduce the effectiveness of some treatments for psoriasis and PsA.2
Smoking
Smoking is linked to an imbalance between unstable atoms that can be damaging and the substances needed to control them in the body. This imbalance is called oxidative stress. It can cause chronic inflammation in the body.2
Smoking increases the risk of other autoimmune diseases like psoriasis and rheumatoid arthritis. So, it is likely that it also increases the risk of PsA. However, more research is needed to confirm this.2
Identifying the risk factors involved in PsA helps doctors diagnose PsA earlier and better understand the disease.