The different subtypes depend on which parts of the body are affected, and the severity of disease.

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Chronic illness is never one-size-fits-all—people who share the same disease often experience different at different intensities and throughout different stages of life.

Psoriatic arthritis (PsA) is just one of those chronic conditions. The autoimmune disease causes inflammation in the joints and occurs along with the skin condition psoriasis—and while that explanation seems simple enough, PsA is actually broken up into five more subcategories, depending on which type of joint is impacted: symmetric psoriatic arthritis, asymmetric psoriatic arthritis, distal psoriatic arthritis, spondylitis, and arthritis mutilans.

what are the 5 types of psoriatic arthritis , Cropped image of woman having knee pains
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Before we dive too deep into these PsA subcategories, it's important to know that, in the grand scheme of things (mainly treatment options), your specific type of PsA doesn't make a huge difference in your care. "We treat them all the same," Magdalena Perez-Rivera, MD, a rheumatology specialist at Conviva Care Centers, tells Health. She adds that sometimes talking about the different types can even "overcomplicate" things for patents and caregivers.

Still, it can be helpful distinguish between PsA types to keep an eye on symptoms, and to nail down specifics about your diagnosis. You may also have more than one type of PsA, or your specific subtype can change over type depending on the progression of your disease. Here, doctors explain the different subtypes of psoriatic arthritis, and the unique symptoms associated with each.

Symmetric polyarthritis

Symmetric polyarthritis, sometimes known as symmetric PsA, affects the joints on both sides of the body (for example, both knees would be affected, instead of just one).

This type of PsA is the most common, accounting for about half of all PsA cases, and it's most like rheumatoid arthritis (RA). Symmetric polyarthritis can affect any joint in the body, according to the US National Library of Medicine (NLM), and symptoms can range from mild to severe.

The most common symptoms associated with symmetric polyarthritis, per the NLM, are:

  • Stiff, painful joints on matching sides of the body
  • Redness, heat, and swelling in the tissue surrounding affected joints
  • A "sausage-like" appearance of fingers or toes from inflammation, when hands or feet are affected.
  • General symptoms of PsA, like patches of red, irritated skin covered in scales, changes in fingernails or toenails, or stiffness and pain that's worse in the morning

Asymmetric oligoarticular

This type of PsA—more commonly known as asymmetric PsA—affects different joints on each side of the body, Elena Schiopu, MD, a rheumatologist at the University of Michigan, tells Health. That means, for example, you may have symptoms in one wrist but not the other, or you may more commonly feel pain and stiffness on one side of the body compared to the other.

The most common symptoms associated with asymmetric oligoarticular, per the NLM, are:

  • Stiff, painful joints on different sides of the body
  • Redness, heat, and swelling in the tissue surrounding affected joints
  • A "sausage-like" appearance of fingers or toes from inflammation, when hands or feet are affected.
  • General symptoms of PsA, like patches of red, irritated skin covered in scales, changes in fingernails or toenails, or stiffness and pain that's worse in the morning

Distal interphalangeal predominant

The distal interphalangeal predominant joints are those on your fingers, closest to your nails—and so, this type of PsA affects mainly the ends of the fingers and toes, according to the NLM.

Nail changes—pitting, ridging, crumbling, or separating from nail beds—are most common with this type of PsA. Distal PsA is also more frequently associated with "sausage digits," or extreme swelling of fingers and toes with the condition. This type of PsA also occurs frequently alongside other types rather than by itself.

The most common symptoms associated with distal interphalangeal predominant, according to our experts, are:

  • Swelling of the entire fingers and toes, often called "sausage digits"
  • Severe nail abnormalities, including pitting, discoloration, separation from the nail bed, or even fungal infections
  • Pain, swelling, and stiffness in fingers and toes
  • General symptoms of PsA, like patches of red, irritated skin covered in scales, changes in fingernails or toenails, or stiffness and pain that's worse in the morning

Spondylitis

This type of PsA involves your spine, specifically your lower back and sacrum (the structure connecting your lumbar vertebrae to your pelvis). "You have inflammation and erosion that eats at the joints and [ultimately] they may fuse," says Dr. Perez-Rivera, "limiting your range of motion in your spine."

Your symptoms may not be limited to your back, however—spondylitis can also affect your neck, hips, feet, legs, and arms.

The most common symptoms associated with spondylitis PsA, according to the NLM, are:

  • Pain and stiffness in the back or neck
  • Impaired movement
  • Pain, stiffness, or impaired movement in arm, leg, hands, and feet joints
  • General symptoms of PsA, like patches of red, irritated skin covered in scales, changes in fingernails or toenails, or stiffness and pain that's worse in the morning

Arthritis mutilans

This type of PsA is the most severe form, but the least common, affecting fewer than 5% of those with PsA, per the NLM. Arthritis mutilans, sometimes known as psoriatic arthritis mutilans, involves more severe inflammation and joint damage in the hands and feet—so much so that it can lead to joint deformation and bone loss.

Symptoms here may also not be limited to only hands and feet—neck and back pain may also occur with arthritis mutilans.

The most common symptoms associated with arthritis mutilans, per the NLM and our experts are:

  • Severe inflammation in joints in the hands and feet
  • Deformation and movement issues in the affected joints
  • Osteolysis, or bone loss, at the joints
  • Telescoping, or shortening, of the fingers and toes
  • Neck and back pain
  • General symptoms of PsA, like patches of red, irritated skin covered in scales, changes in fingernails or toenails, or stiffness and pain that's worse in the morning

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