Psoriatic arthritis is a painful joint condition that can affect people who have the skin condition psoriasis. Psoriasis is an immune system condition that causes the skin to develop red, itchy, rash-like scales. The skin patches can grow especially thick and bothersome when the immune system is compromised, such as when a person develops a cold or an infection.
Over time, a person with psoriasis may also experience swelling and pain in their joints. If the condition is linked to their psoriasis, it is known as psoriatic arthritis. PsA can affect up to 30% of people with psoriasis. Left untreated, PsA can cause permanent joint damage, pain and immobility.
What is Psoriatic Arthritis?
In the same way that psoriasis causes the immune system to attack healthy skin cells, psoriatic arthritis causes the immune system to attack healthy joints and related tissues. PsA is a chronic, inflammatory condition that has no cure. PsA doesn’t usually develop until around ten years after a person develops psoriasis, and most commonly affects people between the ages of 30 and 50. However, some people with psoriasis never develop psoriatic arthritis.
What Causes Psoriatic Arthritis?
While the exact cause of psoriatic arthritis isn’t known, the immune system and genetics are thought to play a role. Other potential risk factors linked to PsA include:
- Having a family history of PsA
- Having severe psoriasis (psoriasis that develops at earlier age and causes larger skin lesions and plaques than normal)
- Exposure to cigarette smoke
- Psoriasis plaques on the scalp and perianal region
- Nail disease (pitted, deformed nail beds)
- Physical trauma (car accidents, work-related accidents, etc.)
- Excessive alcohol intake
It’s important to note that studies supporting these risk factors for PsA are limited in scope. It’s imperative that individuals with psoriasis who suspect they have PsA visit their doctors for ongoing examinations.
What Are the Symptoms of Psoriatic Arthritis?
According to the National Psoriasis Foundation, the main symptoms of PsA include:
- Joint pain, tenderness, and swelling
- Swelling in fingers and toes
- Reduced range of motion
- Stiffness, pain and throbbing at one or more joint sites
- Pain or redness in the eyes
- Stiffness and fatigue in the morning or after resting
According to the Arthritis Foundation, other psoriatic arthritis symptoms include pain and swelling in joints on different sides of the body, particularly in the heels and soles of the feet
How is Psoriatic Arthritis Diagnosed?
There is no single test available to diagnose psoriatic arthritis. However, there are tests that can help your doctor eliminate other conditions that have similar symptoms. Typically, your doctor will ask you questions about your symptoms and perform a complete physical examination. This includes checking your joints for pain, swelling and tenderness, as well as checking your nails for signs of pitting, lifting or cracking. Before receiving a diagnosis of PsA, it’s important for your doctor to perform tests that rule out other types of arthritis, like gout and rheumatoid arthritis. You may also need to undergo x-rays, an MRI or blood tests to help confirm your diagnosis.
Because PsA is often misdiagnosed as other conditions, it’s important to see a specialist that has unique experience in diagnosing and treating PsA. Rheumatologists that specialize in treating psoriasis and psoriatic arthritis may provide more effective diagnosis and treatment than a non-specialist.
How is Psoriatic Arthritis Treated?
While PsA cannot be cured, there are treatment options available to slow the progression of joint damage, restore range of motion and control pain.
NSAIDs are often prescribed to treat mild-to-moderate joint pain by reducing inflammation in the body. Long-term use of NSAIDs can lead to side effects like stomach problems, so consult your doctor before purchasing NSAIDs to treat your PsA joint pain.
Disease-Modifying Antirheumatic Drugs (DMARDs) can help slow the progression of PsA and preserve the joints. However, they can cause serious side effects such as liver damage and even lung infections.
Immunosuppressants can help control PsA symptoms by controlling the immune system response, a common cause of PsA flare-ups. Immune system suppression can make individuals more susceptible to illness, however.
Biologic drugs, given via IV or injection (a shot), specifically target aspects of the immune system that can cause PsA flare ups. Typically, biologics target cytokines and proteins that signal the body to create inflammation. TNF-alpha and Interleukins 12/23 are two proteins that can trigger inflammation in the body. Your doctor or rheumatologist may prescribe tumor necrosis factor alpha inhibitors or interleukin 12/23 inhibitors to slow this inflammation response from these proteins.
Oral medications like Apremilast may also be prescribed to slow the activity of enzymes that control inflammatory activity in cells.
For severe PsA, many individuals turn to surgical interventions like steroid injections or joint replacement surgery for pain relief and increased mobility.