Psoriatic arthritis (PsA) is a kind of arthritis that impacts individuals with the skin condition psoriasis. It’s estimated that PsA affects about 20 to 30 percent of people with psoriasis.

PsA can cause the affected joints to become painful, stiff, and swollen. The condition is different for everyone. Symptoms can range from mild to severe and can impact only a few or several joints.

There are 5 different subtypes of PsA. These are based off of the areas of the body that are affected as well as the severity of symptoms. A person with PsA can also have symptoms consistent with multiple subtypes of PsA.

In this article, we’ll outline the different subtypes of PsA, their symptoms, and how common they are. Then, we’ll cover how PsA is diagnosed and treated. Continue reading to discover more.

Asymmetric PsA impacts a joint or joints on one side of your body. Typically, less than 5 joints are impacted by this type of PsA. Asymmetric PsA is more common in people assigned male at birth.

The Arthritis Foundation notes that most of the time, PsA is asymmetric. It’s estimated that about 60 percent of individuals with PsA initially present with asymmetric PsA. But over time, this can progress to symmetric PsA.

Any joint in the body can be affected by asymmetric PsA. Some areas that are more commonly impacted are the:

  • knee
  • feet
  • ends of the fingers and toes
  • large joints

Symptoms

Symptoms of asymmetric PsA can be mild to severe and can include:

The fact the asymmetric PsA only affects one side of the body can help to distinguish it from other types of arthritis, liker rheumatoid arthritis (RA).

Symmetric PsA impacts five or more of the same joints on both sides of the body. While this type of PsA can occur in any joint, the small joints in the hands and feet are most commonly affected. Symmetric PsA is less common in larger joints.

The incidence of symmetric PsA is estimated to range from 15 to 61 percent. Symmetric PsA is more common in people assigned female at birth.

Symptoms

The symptoms of symmetric PsA are generally the same as those observed in asymmetric PsA. They can also range from mild to severe.

Because this type of PsA is symmetrical and mainly impacts small joints, it can often be mistaken for RA. But it’s generally milder than RA and blood tests for rheumatoid factor (RF) are almost always negative.

Distal interphalangeal (DIP) predominant PsA mainly affects the distal interphalangeal joint. This is the joint that’s closest to the ends of the fingers and toes.

In someone with DIP predominant PsA, it’s estimated that over 50 percent of all impacted joints are DIP joints. This type of PsA can be either symmetrical or asymmetrical and impacts about 10 percent of people with PsA.

Symptoms

In addition to other general symptoms of PsA, nail changes are very common in people with DIP predominant PsA. These can include nail pitting, nail cracking, and separation of the nail from the nail bed (onycholysis).

Spondylitis PsA mainly affects the joints between your spinal vertebrae. You may also see this type of PsA referred to as axial arthritis. It’s thought that spondylitis PsA is present in 7 to 32 percent of people with PsA.

Symptoms

In addition to other general symptoms of PsA, those with spondylitis PsA also experience pain, swelling, and stiffness in the neck and back, which can make movement very difficult.

Even though spondylitis PsA primarily impacts the spine, people with this type of PsA can also experience symptoms in other joints. These can include the:

PsA mutilans is the most severe type of PsA. It’s rare and is estimated to impact about 5 percent of all people with PsA. The small joints of the hands, feet, and wrist are most often affected.

Symptoms

In PsA mutilans, inflammation is very severe, leading to significant damage to the affected joints. This can lead to symptoms like:

  • deformities of the affected joint, which can be serious
  • problems with movement and range of motion
  • bone loss in the affected joint, which can lead to shortening of the fingers or toes

PsA mutilans can also impact other areas as well. People with this type of PsA may also experience pain in their neck and back.

Early diagnosis of PsA is vital. This is because starting treatment as early as possible can help to prevent further joint damage.

A doctor will typically use the following steps to diagnose PsA:

  • Medical history: To get an idea of your medical history, a doctor will ask you a variety of questions, which can include:
    • When did you first notice your symptoms?
    • How would you describe the severity of your symptoms?
    • Is there anything that makes your symptoms better or worse?
    • Do you have a family history of psoriasis or PsA?
    • What medications or supplements are you currently taking?
  • Physical examination: Next, your doctor will perform a physical examination. During this time, they’ll examine your joints for any signs of tenderness and swelling. They’ll also check for movement difficulties or nail changes.
  • Blood tests: Blood tests for PsA look for signs of inflammation and can include tests like those for C-reactive protein (CRP) and rheumatoid factor (RF). A negative test for RF can help to rule out RA.
  • Imaging: Imaging technology can help your doctor to evaluate your joints for signs of inflammation and damage. Examples of imaging techniques that may be used include X-ray and MRI.

There are several potential treatment options for PsA. What’s involved in your specific treatment plan can depend on a variety of factors, including:

  • the severity of your symptoms
  • how many joints are impacted
  • which joints are affected
  • the extent of the damage in the affected joints
  • your responses to previous treatments for PsA
  • your overall health
  • your personal preference

Medications

A variety of medications can be used in the treatment of PsA. Some examples include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs are medications that can work to ease inflammation and pain in mild PsA. They’re available either over-the-counter or by prescription.
  • Disease-modifying antirheumatic drugs (DMARDs): DMARDs are drugs that help to prevent mild to moderate PsA from getting worse. Examples of DMARDs include methotrexate, sulfasalazine, and apremilast (Otezla).
  • Biologics: Biologics are a newer type of DMARD. They’re proteins that target specific parts of the inflammatory process. They may be used for more severe PsA or spondylitis PsA. Examples of biologics are adalimumab (Humira) and secukinumab (Cosentyx).
  • Immunosuppressants: Immunosuppressants are drugs that dampen the activity of your immune system. Due to the availability of biologics, they’re not used as often. Examples include cyclosporine and azathioprine.
  • Corticosteroids: Corticosteroids work to reduce inflammation. They can be given as a pill or an injection. Due to side effects, oral corticosteroids are taken at the lowest dose for the shortest amount of time possible.

Surgery

Surgery can sometimes be used for PsA. But this type of treatment is typically only recommended when PsA has caused joints to become severely damaged.

Exercise

Engaging in regular, low-impact exercises like walking and swimming can also help to keep joints healthy. Physical therapy may also be recommended to improve or maintain strength, flexibility, and range of motion.

PsA is an autoimmune disease. This is where the immune system mistakenly attacks healthy tissues, leading to inflammation and damage.

What exactly causes the immune system to behave this way in people with PsA isn’t clear. It’s believed that a complex combination of genetic and environmental influences may play a role.

About 33 to 50 percent of people with PsA have at least one close relative that has either psoriasis or PsA. Additionally, several genes associated with PsA have been identified.

Environmental factors that may contribute to the development of PsA include things like infections or physical trauma.

PsA is a condition that can affect some individuals with psoriasis. It can cause joint inflammation and pain ranging from mild to severe. The symptoms of PsA can also impact movement and quality of life.

There are 5 different subtypes of PsA. These are divided up based on factors like the affected area and symptom severity. It’s possible for an individual with PsA to experience symptoms that align with multiple subtypes of PsA.

A variety of treatments can help to ease PsA symptoms and slow the progression of the condition. An early diagnosis is important in preventing further joint damage. See a doctor as soon as possible if you’re experiencing symptoms of PsA.