“Psoriatic arthrtis is a lot like rheumatoid arthritis but with a nasty skin rash.”

This probably sounds terrible but I was secretly happy when I heard Phil Mickelson the golfer was what is the difference between psoriatic vs. rheumatoid arthritis?diagnosed with psoriatic arthritis.  Not that I would wish the diagnosis on anyone!  But I thought, wow, maybe it will increase awareness and maybe, just maybe, more studies and treatment options will become available.

I had worked for a rheumatologist/internal medicine doctor back in the early years of my nursing career.  We had patients with rheumatoid arthritis, osteoarthritis, lupus, Sjogren’s, a few cases of temporal arteritis—I even saw my first HIV positive patient working in that clinic in the mid 80’s.  But I never once heard of psoriatic arthritis.  I don’t even remember hearing about it in nursing school—and I still hadn’t heard of psoriatic arthritis when I was diagnosed in my late 40s. I was baffled by my diagnosis partly because I had no idea what it was but also it never even occurred to me since the psoriasis I had on my scalp had been diagnosed as just a bad case of dandruff and my “sausage toes” had been diagnosed as Morton’s Neuroma.

So here I am now, living with psoriatic arthritis.  I’ve had a total hip replacement because of it and I live with its nasty ramifications on a daily basis.  I am now well versed in the world of biologicals, NSAIDs, steroids, physical therapy, arthritis gadgets, shoes, etc.  But I have difficulty trying to explain to others what psoriatic arthritis is; even my own family members don’t really understand what it is.

So what is psoriatic arthritis (PsA) and how does it differ from rheumatoid arthritis (RA)?

Well, just like rheumatoid arthritis, it is an auto-immune disease.  Both cause an erosive inflammatory arthritis (pain, stiffness and swelling) in addition to chronic fatigue.  And both can have symptoms that vary greatly from person to person.  However the distribution of joint involvement differs between the two diseases and psoriatic arthritis involves the skin as well as the joints.

Both diseases can cause destruction of the small joints in your hands and feet as well as larger joints such as knees, hips, shoulders and even the vertebrae in your spine. Classic rheumatoid arthritis primarily involves the PIP joints (the middle joint of your finger and toes) and wrist, and is generally a symmetrical disease effecting both sides of the body equally.  Also with rheumatoid arthritis, nodules specific to this disease are often present.

Psoriatic arthritis is typically an asymmetric disease, involving one side of the body but it can be symmetrical too.  It most often involves the DIP joints (the joints closest to your fingernails and toenails, often resulting in ‘sausage digits’).  Psoriatic arthritis often times will cause an inflammation of the tendons (enthesitis), especially tendinitis in the Achilles tendons and both conditions can cause plantar fasciitis in the soles of the feet which can make walking especially painful.  Psoriatic arthritis  often causes spondylitis which is an inflammation of the joints between the vertebrae in the spine and sacroiliitis which is inflammation in the joints between your spine and pelvis. Somehow, I’ve been blessed with enthesitis, spondylitis, and sacroiliitis.  Lucky me!  Psoriatic arthritis can also involve the fingernails and toenails, and can result in pitting or separation of the nail from the nail bed and may progress to a very destructive deformity called arthritis mutilans.  I’m hoping I don’t get that!  I love my monthly pedicure and having the nail separate from the nail bed would certainly be a bummer!

Both diseases can involve inflammation and scarring of major organs such as your heart and lungs and as in my case can involve your eyes.  In addition, both can increase your risk of osteoporosis (weakened bone) due the condition itself and also from some of the medications that are used to treat these conditions.  After years of taking steroids for my arthritis, it resulted in a couple of compression fractures in my thoracic spine.  And, both disorders can also result in joint destruction leading to severe crippling disabilities.

On the surface rheumatoid arthritis and psoriatic arthritis can look very similar, making diagnosis a little tricky at times.  Psoriatic arthritis is often times referred to as a seronegative arthritis as the person will typically have an elevated sed rate and CRP (blood test that measure inflammation in the body) just like someone with rheumatoid arthritis but they will usually have a negative rheumatoid factor. Treatment for both diseases are similar, using anti-inflammatory agents, DMARD’s, steroids and biologicals. If medications fail to prevent or slow joint damage then surgery is sometimes needed to correct deformities such as total joint replacements, tendon repairs or joint fusions.

So, basically rheumatoid arthritis and psoriatic arthritis are very similar and treatments are generally the same. The biggest difference is the joints involved in the hands and feet and the fact that psoriatic arthritis also involves psoriasis of the skin which is a persistent chronic disease in itself.  Psoriasis causes itchy, dry, red patches and thick silvery scales of the skin that can sometimes be painful and embarrassing!

Psoriatic arthritis involves both the skin and the joints and that is why it often times is referred to as having a ‘Double Whammy’.  So, now when I’m trying to explain it I just say, “It’s a lot like rheumatoid arthritis but with a nasty skin rash.”