Psoriatic Arthritis (PsA) vs. Osteoarthritis (OA): Which Is It?

Psoriatic arthritis and osteoarthritis share some symptoms, but they also have key differences.

Tips for identifying PsA

Symptoms of PsA are often confused with symptoms of OA or rheumatoid arthritis (RA). The key to differentiating between PsA and the other forms of arthritis is to single out unique characteristics.

Some key symptoms that distinguish PsA from other forms of arthritis are:

• Swelling in your fingers or toes: In PsA, the fingers and toes can swell up like sausages. This is called dactylitis.
• Skin rashes: The buildup of skin cells in psoriasis causes the skin to thicken and turn red, and this may be topped with silvery-white patches. You’ll most often notice these rashes, which are called plaques, on your scalp, face, hands, feet, genitals, and in skin folds like your belly button.
• Nail changes: About 80% of people with PsA have nail lesions.

Both OA and PsA affect similar joints, including the lower back, fingers, toes, and knees. But while OA pain is consistent, PsA symptoms come and go. In other words, the symptoms of the condition grow worse for a period of time and then go into remission, which is a period of inactivity.

Tips for identifying OA

OA isn’t a disease that cycles. Instead, it can gradually get worse.

Your OA pain may be mild at first — for example, you might notice a slight twinge in your knee when you bend it, or your joints might ache after a workout.

The pain, swelling, and stiffness will get worse as the joint damage increases. Along with the pain, your joints will feel stiff — especially when you first wake up in the morning.

OA will most likely affect the joints of your body that move the most. This includes the joints in your:

• hands
• feet
• knees
• hips
• spine

PsA is an autoimmune disease. This means your body mistakenly attacks its own cells.

PsA typically only develops in people who have psoriasis, a common skin condition that causes rapid skin cell buildup. About 20% of people with psoriasis have PsA.

In most people with PsA, psoriasis develops first, and arthritis comes later.

Additional risk factors for PsA include:

• Family history: People with a parent, sibling, or other close relative who has psoriasis or PsA are more likely to also develop the condition.
• Age: PsA can develop at any age, but it’s most commonly diagnosed in people ages 30–50 years.
• Infections: People who are exposed to certain viruses, such as HIV, are more likely to get PsA.

Treatments for PsA aim to do two things: Slow or stop the joint damage and relieve pain.

A typical treatment plan will involve one or more of the following:

• medication
• steroid injections
• joint replacement surgery
• alternative remedies

There are also treatments for psoriasis skin rashes and nail changes.

Medications and injections

Nonsteroidal anti-inflammatory drugs (NSAIDs) relieve pain and reduce swelling in your joints. Some of these medications are available over the counter (OTC), while others require a prescription from your doctor.

OTC options include ibuprofen (Advil) and naproxen (Aleve).

Common prescription options include:

• diclofenac (Voltaren)
• ketoprofen (Orudis)
• meclofenamate (Meclomen)
• meloxicam (Mobic)
• nabumetone (Relafen)
• oxaprozin (Daypro)
• tolmetin (Tolectin)

Disease-modifying antirheumatic drugs (DMARDs) reduce the overactive immune system response. They can slow or stop joint damage.

Commonly prescribed DMARDs include:

• cyclosporine (Sandimmune)
• hydroxychloroquine (Plaquenil)
• azathioprine (Imuran)
• leflunomide (Arava)
• methotrexate (Trexall)
• sulfasalazine (Azulfidine)

New guidelines recommend biologic drugs as first-line treatments for PsA. These drugs work on specific parts of your immune system to stop joint damage. You get them as an injection or infusion.

Commonly prescribed biologic drugs include:

• adalimumab (Humira)
• certolizumab pegol (Cimzia)
• etanercept (Enbrel)
• golimumab (Simponi)
• infliximab (Remicade)
• secukinumab (Cosentyx)
• ustekinumab (Stelara)

New drugs for PsA target certain molecules inside the immune cell. One such drug is apremilast (Otezla).

In addition to these medications, steroid injections administered into the affected joint can bring down swelling and relieve pain. If the joint has severe damage, surgery is an option to fix or replace it.

Alternative treatments

Research has looked into a few alternative treatments, but none of them have been shown to have a significant effect on PsA symptoms. It is not advisable to use these as a replacement, and it’s important to speak with your doctor before trying anything new:

• acupuncture
• herbal remedies such as capsaicin or turmeric
• massage
• tai chi
• yoga

Treatments targeting psoriasis symptoms

Some of the medications that manage arthritis symptoms, like biologics and methotrexate, also treat psoriasis skin symptoms. Other treatments for the skin include:

• anthralin (Dritho-Scalp)
• coal tar
• retinoid creams, such as tazarotene (Tazorac)
• salicylic acid
• steroid creams and ointments
• vitamin D-based creams, such as calcipotriene (Dovonex)

You can also try light therapy (phototherapy). This treatment uses ultraviolet light to clear plaques on your skin.

Physical or occupational therapies are recommended for PsA patients to maintain joint health and improve their quality of life.

OA causes the cartilage inside the joints to break down and wear away. Cartilage is the flexible connective tissue that surrounds the ends of your bones.

In healthy joints, cartilage helps cushion the movement of the joint and absorbs the shock of impact when you move. When you have OA, the layers of your cartilage begin to break down.

Without cartilage, your bones rub against each other, causing pain. This can lead to permanent damage to both your joints and your bones.

These risk factors can increase your chances of developing OA:

• Genes: Certain inherited genetic changes may increase your odds of developing OA. If a family member has the disease, it’s possible you’ll also develop it.
• Age: Your likelihood of getting this type of arthritis increases as you age.
• Gender: Women are more likely than men to develop all kinds of arthritis, including OA.
• Weight: People who have overweight or obesity have a higher risk of OA because these conditions can cause extra strain on their joints.
• Joint damage: If you’ve experienced a joint injury or your joints didn’t form properly, they can get damaged more easily.
• Smoking: Tobacco smoking doesn’t cause OA, but it can accelerate cartilage damage.

OA treatment aims to reduce the symptoms of the condition.

A typical treatment plan will include one or more of the following:

• medication
• injections
• exercise or physical therapy
• joint support, such as braces
• alternative remedies

If your joint is badly damaged, you may need surgery. OA surgery replaces the damaged joint with an artificial joint made from plastic or metal.

Medication

Medications for OA relieve joint pain and swelling.

OTC options include acetaminophen (Tylenol) and NSAIDs, such as ibuprofen (Advil) and naproxen (Aleve). Duloxetine (Cymbalta) is available by prescription only.

Some medications are injected right into the joint to reduce inflammation and increase movement. These include corticosteroids and hyaluronic acid.

Alternative treatments

Alternative treatments can help you manage symptoms and cope with changes in your mobility as OA progresses.

Popular options include:

• acupuncture
• assistive devices, such as splints, shoe orthotics, canes, walkers, and scooters
• massage
• meditation and other relaxation techniques
• occupational therapy
• physical therapy
• water therapy

Exercise

Exercise strengthens the muscles that support your joints. Regular physical activity can also help manage your body weight, which can alleviate stress on the joints in your knees and hips.

The ideal exercise program for OA combines low impact aerobics with strength training. Add in yoga, Pilates, or tai chi to improve your flexibility.

If you have joint pain, swelling, and stiffness that doesn’t go away after a few weeks, it’s advisable to see your doctor. You should also see your doctor if you notice a rash in areas like your scalp, face, or under your arms.

If you do have PsA or OA, starting treatments and making lifestyle changes can help you limit further damage and preserve the joint strength you still have.