Understanding Psoriasis, Psoriatic Arthritis and Their Differences

Psoriasis affects more than 3% of the US adult population. That is more than 7.5 million US adults.

Psoriasis is an auto-immune disorder that creates an inflammatory response within the body. Visible signs of the disease can result in raised plaque areas on the skin. These plaque and scaly patches occur because the skin cells of an overactive immune system do not shed at a normal rate, thus “piling” up on the surface. This disease can also affect other organs and tissues in the body, with one in three people developing psoriatic arthritis (PsA). PsA includes swelling, stiffness, and pain in the joints – as well as the surrounding areas. Although there is no cure, there are effective treatments for psoriasis. Treatment and early intervention are key to lowering the risk of developing other health conditions such as heart disease, obesity, diabetes, and depression.

What Is Psoriasis?

Psoriasis is an immune-mediated disease (a disease with an unclear cause that is characterized by inflammation caused by dysfunction of the immune system) that causes inflammation in the body. There may be visible signs of the inflammation, such as raised plaques (plaques may look different for different skin types) and scales on the skin.

This occurs because the overactive immune system speeds up skin cell growth. Normal skin cells completely grow and shed (fall off) in a month. With psoriasis, skin cells do this in only three or four days. Instead of shedding, the skin cells pile up on the surface of the skin. Some people report that psoriasis plaques itch, burn, and sting. Plaques and scales may appear on any part of the body, although they are commonly found on the elbows, knees, and scalp.

Inflammation caused by psoriasis can impact other organs and tissues in the body. People with psoriasis may also experience other health conditions.

One in three people with psoriasis may also develop psoriatic arthritis. Signs of PsA include swelling, stiffness and pain in the joints and areas surrounding the joints. PsA often goes undiagnosed, particularly in its milder forms. However, it’s important to treat PsA early on to help avoid permanent joint damage. Symptoms often start between ages 15 and 25 but can start at any age. Men, women, and children of all skin colors can get psoriasis.

Although there is no cure, there are more effective treatments for psoriasis today than ever before. Treating psoriasis can help improve symptoms and lower the risk of developing other health conditions, such as psoriatic arthritis, heart disease, obesity, diabetes, and depression.

Psoriatic arthritis affects about 30% of people with psoriasis.

Psoriatic arthritis (PsA) is a chronic, inflammatory disease of the joints and where tendons and ligaments connect to bone. Like psoriasis, PsA is associated with related health conditions (comorbidities).

The condition can start at any age and often appears between ages 30 and 50. For many people, it starts about ten years after psoriasis develops, but some develop PsA first or without ever developing or noticing psoriasis.

Though there is no cure, a growing range of treatments are available to help stop the disease progression, lessen pain, protect joints, and preserve range of motion. If you have or suspect you may have PsA, it is extremely important to work with a rheumatologist (a doctor who specializes in how the immune system affects joints, bones, and muscles) to find the right treatment plan.

Early recognition, diagnosis, and treatment of PsA can prevent or limit the extensive joint damage that can occur in the later stages of the disease.

Symptoms of PsA

PsA can develop slowly, with mild symptoms, or it can develop quickly and severely. Some people may develop PsA in a joint after an injury. Development may also be related to genetics. Scientists estimate that at least 10 percent of the general population inherits one or more of the genes that create a predisposition to psoriasis.

Common symptoms:

Fatigue
Tenderness, pain, and swelling over tendons
Swollen fingers and toes that sometimes resemble sausages
Stiffness, pain, throbbing, swelling, and tenderness in one or more joints
Reduced range of motion
Morning stiffness and tiredness
Nail changes, such as pitting or separation from the nail bed
Redness and pain in the eye (uveitis)
There is little connection between psoriasis severity and PsA severity. You could have few skin lesions but many joints affected by arthritis.