What's the difference between osteoarthritis and psoriatic arthritis?

Arthritis is a general term for joint pain or joint disease, and there are over 100 different kinds. It can affect people at any age, and it’s the most common cause of disability in the United States.

Osteoarthritis (OA) is the most common chronic joint condition in adults. It's a wear-and-tear type of arthritis that happens when cartilage breaks down in your joints, and it usually affects the hands, hips, knees, and lower back. One of the biggest risk factors for osteoarthritis is aging, which is why this type of joint pain is associated with getting on in years. 

But there’s another type of arthritis that can affect people who have the autoimmune disease psoriasis, where the immune system attacks your skin and sometimes other organs. It is called psoriatic arthritis (PsA), and it happens when your immune system attacks your joints.

Unfortunately, many people who have psoriasis shrug off joint pain as they get older. A 2015 review of 12 different studies found that about 15 percent of people with psoriasis have undiagnosed PsA. Why does PsA get missed? When you're seeing your dermatologist, you're both focused on your skin, while a primary healthcare provider (HCP) might not be tuned into the signs of PsA. 

Oddly enough, you could have PsA even if you don’t have psoriasis symptoms. In these cases, people often do have a family history of the skin disease or PsA, though.

What's the difference between osteoarthritis and psoriatic arthritis symptoms? 

Telltale signs to look out for with PsA include: 

• Pain and swelling that comes and goes (called flare-ups) 
• Pain that usually gets better with exercise 
• Tender spots where tendons and ligaments connect with bones, often around the heel, sole of the foot, and elbows 
• Fatigue or exhaustion 
• Eye pain or redness 
• Fingernails or toenails that look pitted and separated from the nail bed 
• Painful, sausage-like swelling in the fingers or toes 

Signs of osteoarthritis include: 

• A cracking sound or a scraping or grating feeling when you bend your joints 
• Pain that usually gets worse with activity and better with rest 
• Bone spurs that can be felt under the skin 
• Mild swelling, but this is less common 

As if this weren’t confusing enough, there are other types of autoimmune arthritis, such as rheumatoid arthritis.

The bottom line? If you have joint pain—especially if you have psoriasis—tell an HCP. You don’t want PsA or another type or arthritis to go undiagnosed and potentially cause more damage. The sooner you figure out why your joints hurt, the better. Early treatment may help protect your joints from permanent damage.